diff --git a/t/unit-tests/clar/.github/workflows/ci.yml b/t/unit-tests/clar/.github/workflows/ci.yml
new file mode 100644
index 0000000000..b1ac2de460
--- /dev/null
+++ b/t/unit-tests/clar/.github/workflows/ci.yml
@@ -0,0 +1,23 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os: [ ubuntu-latest, macos-latest ]
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+    - name: Check out
+      uses: actions/checkout@v2
+    - name: Build
+      run: |
+        cd test
+        make
diff --git a/t/unit-tests/clar/COPYING b/t/unit-tests/clar/COPYING
new file mode 100644
index 0000000000..8983817f0c
--- /dev/null
+++ b/t/unit-tests/clar/COPYING
@@ -0,0 +1,15 @@
+ISC License
+
+Copyright (c) 2011-2015 Vicent Marti
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/t/unit-tests/clar/README.md b/t/unit-tests/clar/README.md
new file mode 100644
index 0000000000..a8961c5f10
--- /dev/null
+++ b/t/unit-tests/clar/README.md
@@ -0,0 +1,329 @@
+Come out and Clar
+=================
+
+In Catalan, "clar" means clear, easy to perceive.  Using clar will make it
+easy to test and make clear the quality of your code.
+
+> _Historical note_
+>
+> Originally the clar project was named "clay" because the word "test" has its
+> roots in the latin word *"testum"*, meaning "earthen pot", and *"testa"*,
+> meaning "piece of burned clay"?
+>
+> This is because historically, testing implied melting metal in a pot to
+> check its quality.  Clay is what tests are made of.
+
+## Quick Usage Overview
+
+Clar is a minimal C unit testing framework. It's been written to replace the
+old framework in [libgit2][libgit2], but it's both very versatile and
+straightforward to use.
+
+Can you count to funk?
+
+- **Zero: Initialize test directory**
+
+    ~~~~ sh
+    $ mkdir tests
+    $ cp -r $CLAR_ROOT/clar* tests
+    $ cp $CLAR_ROOT/test/clar_test.h tests
+    $ cp $CLAR_ROOT/test/main.c.sample tests/main.c
+    ~~~~
+
+- **One: Write some tests**
+
+    File: tests/adding.c:
+
+    ~~~~ c
+    /* adding.c for the "Adding" suite */
+    #include "clar.h"
+
+    static int *answer;
+
+    void test_adding__initialize(void)
+    {
+        answer = malloc(sizeof(int));
+        cl_assert_(answer != NULL, "No memory left?");
+        *answer = 42;
+    }
+
+    void test_adding__cleanup(void)
+    {
+        free(answer);
+    }
+
+    void test_adding__make_sure_math_still_works(void)
+    {
+        cl_assert_(5 > 3, "Five should probably be greater than three");
+        cl_assert_(-5 < 2, "Negative numbers are small, I think");
+        cl_assert_(*answer == 42, "The universe is doing OK. And the initializer too.");
+    }
+    ~~~~~
+
+- **Two: Build the test executable**
+
+    ~~~~ sh
+    $ cd tests
+    $ $CLAR_PATH/generate.py .
+    Written `clar.suite` (1 suites)
+    $ gcc -I. clar.c main.c adding.c -o testit
+    ~~~~
+
+- **Funk: Funk it.**
+
+    ~~~~ sh
+    $ ./testit
+    ~~~~
+
+## The Clar Test Suite
+
+Writing a test suite is pretty straightforward. Each test suite is a `*.c`
+file with a descriptive name: this encourages modularity.
+
+Each test suite has optional initialize and cleanup methods. These methods
+will be called before and after running **each** test in the suite, even if
+such test fails. As a rule of thumb, if a test needs a different initializer
+or cleanup method than another test in the same module, that means it
+doesn't belong in that module. Keep that in mind when grouping tests
+together.
+
+The `initialize` and `cleanup` methods have the following syntax, with
+`suitename` being the current suite name, e.g. `adding` for the `adding.c`
+suite.
+
+~~~~ c
+void test_suitename__initialize(void)
+{
+    /* init */
+}
+
+void test_suitename__cleanup(void)
+{
+    /* cleanup */
+}
+~~~~
+
+These methods are encouraged to use static, global variables to store the state
+that will be used by all tests inside the suite.
+
+~~~~ c
+static git_repository *_repository;
+
+void test_status__initialize(void)
+{
+    create_tmp_repo(STATUS_REPO);
+    git_repository_open(_repository, STATUS_REPO);
+}
+
+void test_status__cleanup(void)
+{
+    git_repository_close(_repository);
+    git_path_rm(STATUS_REPO);
+}
+
+void test_status__simple_test(void)
+{
+    /* do something with _repository */
+}
+~~~~
+
+Writing the actual tests is just as straightforward. Tests have the
+`void test_suitename__test_name(void)` signature, and they should **not**
+be static. Clar will automatically detect and list them.
+
+Tests are run as they appear on their original suites: they have no return
+value. A test is considered "passed" if it doesn't raise any errors. Check
+the "Clar API" section to see the various helper functions to check and
+raise errors during test execution.
+
+__Caution:__ If you use assertions inside of `test_suitename__initialize`,
+make sure that you do not rely on `__initialize` being completely run
+inside your `test_suitename__cleanup` function. Otherwise you might
+encounter ressource cleanup twice.
+
+## How does Clar work?
+
+To use Clar:
+
+1. copy the Clar boilerplate to your test directory
+2. copy (and probably modify) the sample `main.c` (from
+   `$CLAR_PATH/test/main.c.sample`)
+3. run the Clar mixer (a.k.a. `generate.py`) to scan your test directory and
+   write out the test suite metadata.
+4. compile your test files and the Clar boilerplate into a single test
+   executable
+5. run the executable to test!
+
+The Clar boilerplate gives you a set of useful test assertions and features
+(like accessing or making sandbox copies of fixture data).  It consists of
+the `clar.c` and `clar.h` files, plus the code in the `clar/` subdirectory.
+You should not need to edit these files.
+
+The sample `main.c` (i.e. `$CLAR_PATH/test/main.c.sample`) file invokes
+`clar_test(argc, argv)` to run the tests.  Usually, you will edit this file
+to perform any framework specific initialization and teardown that you need.
+
+The Clar mixer (`generate.py`) recursively scans your test directory for
+any `.c` files, parses them, and writes the `clar.suite` file with all of
+the metadata about your tests.  When you build, the `clar.suite` file is
+included into `clar.c`.
+
+The mixer can be run with **Python 2.5, 2.6, 2.7, 3.0, 3.1, 3.2 and PyPy 1.6**.
+
+Commandline usage of the mixer is as follows:
+
+    $ ./generate.py .
+
+Where `.` is the folder where all the test suites can be found. The mixer
+will automatically locate all the relevant source files and build the
+testing metadata. The metadata will be written to `clar.suite`, in the same
+folder as all the test suites. This file is included by `clar.c` and so
+must be accessible via `#include` when building the test executable.
+
+    $ gcc -I. clar.c main.c suite1.c test2.c -o run_tests
+
+**Note that the Clar mixer only needs to be ran when adding new tests to a
+suite, in order to regenerate the metadata**. As a result, the `clar.suite`
+file can be checked into version control if you wish to be able to build
+your test suite without having to re-run the mixer.
+
+This is handy when e.g. generating tests in a local computer, and then
+building and testing them on an embedded device or a platform where Python
+is not available.
+
+### Fixtures
+
+Clar can create sandboxed fixtures for you to use in your test. You'll need to compile *clar.c* with an additional `CFLAG`, `-DCLAR_FIXTURE_PATH`. This should be an absolute path to your fixtures directory.
+
+Once that's done, you can use the fixture API as defined below.
+
+## The Clar API
+
+Clar makes the following methods available from all functions in a test
+suite.
+
+-   `cl_must_pass(call)`, `cl_must_pass_(call, message)`: Verify that the given
+    function call passes, in the POSIX sense (returns a value greater or equal
+    to 0).
+
+-   `cl_must_fail(call)`, `cl_must_fail_(call, message)`: Verify that the given
+    function call fails, in the POSIX sense (returns a value less than 0).
+
+-   `cl_assert(expr)`, `cl_assert_(expr, message)`: Verify that `expr` is true.
+
+-   `cl_check_pass(call)`, `cl_check_pass_(call, message)`: Verify that the
+    given function call passes, in the POSIX sense (returns a value greater or
+    equal to 0). If the function call doesn't succeed, a test failure will be
+    logged but the test's execution will continue.
+
+-   `cl_check_fail(call)`, `cl_check_fail_(call, message)`: Verify that the
+    given function call fails, in the POSIX sense (returns a value less than
+    0). If the function call doesn't fail, a test failure will be logged but
+    the test's execution will continue.
+
+-   `cl_check(expr)`: Verify that `expr` is true. If `expr` is not
+    true, a test failure will be logged but the test's execution will continue.
+
+-   `cl_fail(message)`: Fail the current test with the given message.
+
+-   `cl_warning(message)`: Issue a warning. This warning will be
+    logged as a test failure but the test's execution will continue.
+
+-   `cl_set_cleanup(void (*cleanup)(void *), void *opaque)`: Set the cleanup
+    method for a single test. This method will be called with `opaque` as its
+    argument before the test returns (even if the test has failed).
+    If a global cleanup method is also available, the local cleanup will be
+    called first, and then the global.
+
+-   `cl_assert_equal_i(int,int)`: Verify that two integer values are equal.
+    The advantage of this over a simple `cl_assert` is that it will format
+    a much nicer error report if the values are not equal.
+
+-   `cl_assert_equal_s(const char *,const char *)`: Verify that two strings
+    are equal.  The expected value can also be NULL and this will correctly
+    test for that.
+
+-   `cl_fixture_sandbox(const char *)`: Sets up a sandbox for a fixture
+    so that you can mutate the file directly.
+
+-   `cl_fixture_cleanup(const char *)`: Tears down the previous fixture
+    sandbox.
+
+-   `cl_fixture(const char *)`: Gets the full path to a fixture file.
+
+Please do note that these methods are *always* available whilst running a
+test, even when calling auxiliary/static functions inside the same file.
+
+It's strongly encouraged to perform test assertions in auxiliary methods,
+instead of returning error values. This is considered good Clar style.
+
+Style Example:
+
+~~~~ c
+/*
+ * Bad style: auxiliary functions return an error code
+ */
+
+static int check_string(const char *str)
+{
+    const char *aux = process_string(str);
+
+    if (aux == NULL)
+        return -1;
+
+    return strcmp(my_function(aux), str) == 0 ? 0 : -1;
+}
+
+void test_example__a_test_with_auxiliary_methods(void)
+{
+    cl_must_pass_(
+        check_string("foo"),
+        "String differs after processing"
+    );
+
+    cl_must_pass_(
+        check_string("bar"),
+        "String differs after processing"
+    );
+}
+~~~~
+
+~~~~ c
+/*
+ * Good style: auxiliary functions perform assertions
+ */
+
+static void check_string(const char *str)
+{
+    const char *aux = process_string(str);
+
+    cl_assert_(
+        aux != NULL,
+        "String processing failed"
+    );
+
+    cl_assert_(
+        strcmp(my_function(aux), str) == 0,
+        "String differs after processing"
+    );
+}
+
+void test_example__a_test_with_auxiliary_methods(void)
+{
+    check_string("foo");
+    check_string("bar");
+}
+~~~~
+
+About Clar
+==========
+
+Clar has been written from scratch by [Vicent Martí](https://github.com/vmg),
+to replace the old testing framework in [libgit2][libgit2].
+
+Do you know what languages are *in* on the SF startup scene? Node.js *and*
+Latin.  Follow [@vmg](https://www.twitter.com/vmg) on Twitter to
+receive more lessons on word etymology. You can be hip too.
+
+
+[libgit2]: https://github.com/libgit2/libgit2
diff --git a/t/unit-tests/clar/clar.c b/t/unit-tests/clar/clar.c
new file mode 100644
index 0000000000..3fc2c76815
--- /dev/null
+++ b/t/unit-tests/clar/clar.c
@@ -0,0 +1,842 @@
+/*
+ * Copyright (c) Vicent Marti. All rights reserved.
+ *
+ * This file is part of clar, distributed under the ISC license.
+ * For full terms see the included COPYING file.
+ */
+#include <assert.h>
+#include <setjmp.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <stdarg.h>
+#include <wchar.h>
+#include <time.h>
+
+/* required for sandboxing */
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#ifdef _WIN32
+#	include <windows.h>
+#	include <io.h>
+#	include <shellapi.h>
+#	include <direct.h>
+
+#	define _MAIN_CC __cdecl
+
+#	ifndef stat
+#		define stat(path, st) _stat(path, st)
+#	endif
+#	ifndef mkdir
+#		define mkdir(path, mode) _mkdir(path)
+#	endif
+#	ifndef chdir
+#		define chdir(path) _chdir(path)
+#	endif
+#	ifndef access
+#		define access(path, mode) _access(path, mode)
+#	endif
+#	ifndef strdup
+#		define strdup(str) _strdup(str)
+#	endif
+#	ifndef strcasecmp
+#		define strcasecmp(a,b) _stricmp(a,b)
+#	endif
+
+#	ifndef __MINGW32__
+#		pragma comment(lib, "shell32")
+#		ifndef strncpy
+#			define strncpy(to, from, to_size) strncpy_s(to, to_size, from, _TRUNCATE)
+#		endif
+#		ifndef W_OK
+#			define W_OK 02
+#		endif
+#		ifndef S_ISDIR
+#			define S_ISDIR(x) ((x & _S_IFDIR) != 0)
+#		endif
+#		define p_snprintf(buf,sz,fmt,...) _snprintf_s(buf,sz,_TRUNCATE,fmt,__VA_ARGS__)
+#	else
+#		define p_snprintf snprintf
+#	endif
+
+#	ifndef PRIuZ
+#		define PRIuZ "Iu"
+#	endif
+#	ifndef PRIxZ
+#		define PRIxZ "Ix"
+#	endif
+
+#	if defined(_MSC_VER) || defined(__MINGW32__)
+	typedef struct stat STAT_T;
+#	else
+	typedef struct _stat STAT_T;
+#	endif
+#else
+#	include <sys/wait.h> /* waitpid(2) */
+#	include <unistd.h>
+#	define _MAIN_CC
+#	define p_snprintf snprintf
+#	ifndef PRIuZ
+#		define PRIuZ "zu"
+#	endif
+#	ifndef PRIxZ
+#		define PRIxZ "zx"
+#	endif
+	typedef struct stat STAT_T;
+#endif
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+
+#include "clar.h"
+
+static void fs_rm(const char *_source);
+static void fs_copy(const char *_source, const char *dest);
+
+#ifdef CLAR_FIXTURE_PATH
+static const char *
+fixture_path(const char *base, const char *fixture_name);
+#endif
+
+struct clar_error {
+	const char *file;
+	const char *function;
+	size_t line_number;
+	const char *error_msg;
+	char *description;
+
+	struct clar_error *next;
+};
+
+struct clar_explicit {
+	size_t suite_idx;
+	const char *filter;
+
+	struct clar_explicit *next;
+};
+
+struct clar_report {
+	const char *test;
+	int test_number;
+	const char *suite;
+
+	enum cl_test_status status;
+	time_t start;
+	double elapsed;
+
+	struct clar_error *errors;
+	struct clar_error *last_error;
+
+	struct clar_report *next;
+};
+
+struct clar_summary {
+	const char *filename;
+	FILE *fp;
+};
+
+static struct {
+	enum cl_test_status test_status;
+
+	const char *active_test;
+	const char *active_suite;
+
+	int total_skipped;
+	int total_errors;
+
+	int tests_ran;
+	int suites_ran;
+
+	enum cl_output_format output_format;
+
+	int report_errors_only;
+	int exit_on_error;
+	int verbosity;
+
+	int write_summary;
+	char *summary_filename;
+	struct clar_summary *summary;
+
+	struct clar_explicit *explicit;
+	struct clar_explicit *last_explicit;
+
+	struct clar_report *reports;
+	struct clar_report *last_report;
+
+	void (*local_cleanup)(void *);
+	void *local_cleanup_payload;
+
+	jmp_buf trampoline;
+	int trampoline_enabled;
+
+	cl_trace_cb *pfn_trace_cb;
+	void *trace_payload;
+
+} _clar;
+
+struct clar_func {
+	const char *name;
+	void (*ptr)(void);
+};
+
+struct clar_suite {
+	const char *name;
+	struct clar_func initialize;
+	struct clar_func cleanup;
+	const struct clar_func *tests;
+	size_t test_count;
+	int enabled;
+};
+
+/* From clar_print_*.c */
+static void clar_print_init(int test_count, int suite_count, const char *suite_names);
+static void clar_print_shutdown(int test_count, int suite_count, int error_count);
+static void clar_print_error(int num, const struct clar_report *report, const struct clar_error *error);
+static void clar_print_ontest(const char *suite_name, const char *test_name, int test_number, enum cl_test_status failed);
+static void clar_print_onsuite(const char *suite_name, int suite_index);
+static void clar_print_onabort(const char *msg, ...);
+
+/* From clar_sandbox.c */
+static void clar_unsandbox(void);
+static int clar_sandbox(void);
+
+/* From summary.h */
+static struct clar_summary *clar_summary_init(const char *filename);
+static int clar_summary_shutdown(struct clar_summary *fp);
+
+/* Load the declarations for the test suite */
+#include "clar.suite"
+
+
+#define CL_TRACE(ev)													\
+	do {																\
+		if (_clar.pfn_trace_cb)											\
+			_clar.pfn_trace_cb(ev,										\
+							   _clar.active_suite,						\
+							   _clar.active_test,						\
+							   _clar.trace_payload);					\
+	} while (0)
+
+void cl_trace_register(cl_trace_cb *cb, void *payload)
+{
+	_clar.pfn_trace_cb = cb;
+	_clar.trace_payload = payload;
+}
+
+
+/* Core test functions */
+static void
+clar_report_errors(struct clar_report *report)
+{
+	struct clar_error *error;
+	int i = 1;
+
+	for (error = report->errors; error; error = error->next)
+		clar_print_error(i++, _clar.last_report, error);
+}
+
+static void
+clar_report_all(void)
+{
+	struct clar_report *report;
+	struct clar_error *error;
+	int i = 1;
+
+	for (report = _clar.reports; report; report = report->next) {
+		if (report->status != CL_TEST_FAILURE)
+			continue;
+
+		for (error = report->errors; error; error = error->next)
+			clar_print_error(i++, report, error);
+	}
+}
+
+#ifdef WIN32
+# define clar_time DWORD
+
+static void clar_time_now(clar_time *out)
+{
+	*out = GetTickCount();
+}
+
+static double clar_time_diff(clar_time *start, clar_time *end)
+{
+	return ((double)*end - (double)*start) / 1000;
+}
+#else
+# include <sys/time.h>
+
+# define clar_time struct timeval
+
+static void clar_time_now(clar_time *out)
+{
+	struct timezone tz;
+
+	gettimeofday(out, &tz);
+}
+
+static double clar_time_diff(clar_time *start, clar_time *end)
+{
+	return ((double)end->tv_sec + (double)end->tv_usec / 1.0E6) -
+	       ((double)start->tv_sec + (double)start->tv_usec / 1.0E6);
+}
+#endif
+
+static void
+clar_run_test(
+	const struct clar_suite *suite,
+	const struct clar_func *test,
+	const struct clar_func *initialize,
+	const struct clar_func *cleanup)
+{
+	clar_time start, end;
+
+	_clar.trampoline_enabled = 1;
+
+	CL_TRACE(CL_TRACE__TEST__BEGIN);
+
+	_clar.last_report->start = time(NULL);
+	clar_time_now(&start);
+
+	if (setjmp(_clar.trampoline) == 0) {
+		if (initialize->ptr != NULL)
+			initialize->ptr();
+
+		CL_TRACE(CL_TRACE__TEST__RUN_BEGIN);
+		test->ptr();
+		CL_TRACE(CL_TRACE__TEST__RUN_END);
+	}
+
+	clar_time_now(&end);
+
+	_clar.trampoline_enabled = 0;
+
+	if (_clar.last_report->status == CL_TEST_NOTRUN)
+		_clar.last_report->status = CL_TEST_OK;
+
+	_clar.last_report->elapsed = clar_time_diff(&start, &end);
+
+	if (_clar.local_cleanup != NULL)
+		_clar.local_cleanup(_clar.local_cleanup_payload);
+
+	if (cleanup->ptr != NULL)
+		cleanup->ptr();
+
+	CL_TRACE(CL_TRACE__TEST__END);
+
+	_clar.tests_ran++;
+
+	/* remove any local-set cleanup methods */
+	_clar.local_cleanup = NULL;
+	_clar.local_cleanup_payload = NULL;
+
+	if (_clar.report_errors_only) {
+		clar_report_errors(_clar.last_report);
+	} else {
+		clar_print_ontest(suite->name, test->name, _clar.tests_ran, _clar.last_report->status);
+	}
+}
+
+static void
+clar_run_suite(const struct clar_suite *suite, const char *filter)
+{
+	const struct clar_func *test = suite->tests;
+	size_t i, matchlen;
+	struct clar_report *report;
+	int exact = 0;
+
+	if (!suite->enabled)
+		return;
+
+	if (_clar.exit_on_error && _clar.total_errors)
+		return;
+
+	if (!_clar.report_errors_only)
+		clar_print_onsuite(suite->name, ++_clar.suites_ran);
+
+	_clar.active_suite = suite->name;
+	_clar.active_test = NULL;
+	CL_TRACE(CL_TRACE__SUITE_BEGIN);
+
+	if (filter) {
+		size_t suitelen = strlen(suite->name);
+		matchlen = strlen(filter);
+		if (matchlen <= suitelen) {
+			filter = NULL;
+		} else {
+			filter += suitelen;
+			while (*filter == ':')
+				++filter;
+			matchlen = strlen(filter);
+
+			if (matchlen && filter[matchlen - 1] == '$') {
+				exact = 1;
+				matchlen--;
+			}
+		}
+	}
+
+	for (i = 0; i < suite->test_count; ++i) {
+		if (filter && strncmp(test[i].name, filter, matchlen))
+			continue;
+
+		if (exact && strlen(test[i].name) != matchlen)
+			continue;
+
+		_clar.active_test = test[i].name;
+
+		report = calloc(1, sizeof(struct clar_report));
+		report->suite = _clar.active_suite;
+		report->test = _clar.active_test;
+		report->test_number = _clar.tests_ran;
+		report->status = CL_TEST_NOTRUN;
+
+		if (_clar.reports == NULL)
+			_clar.reports = report;
+
+		if (_clar.last_report != NULL)
+			_clar.last_report->next = report;
+
+		_clar.last_report = report;
+
+		clar_run_test(suite, &test[i], &suite->initialize, &suite->cleanup);
+
+		if (_clar.exit_on_error && _clar.total_errors)
+			return;
+	}
+
+	_clar.active_test = NULL;
+	CL_TRACE(CL_TRACE__SUITE_END);
+}
+
+static void
+clar_usage(const char *arg)
+{
+	printf("Usage: %s [options]\n\n", arg);
+	printf("Options:\n");
+	printf("  -sname        Run only the suite with `name` (can go to individual test name)\n");
+	printf("  -iname        Include the suite with `name`\n");
+	printf("  -xname        Exclude the suite with `name`\n");
+	printf("  -v            Increase verbosity (show suite names)\n");
+	printf("  -q            Only report tests that had an error\n");
+	printf("  -Q            Quit as soon as a test fails\n");
+	printf("  -t            Display results in tap format\n");
+	printf("  -l            Print suite names\n");
+	printf("  -r[filename]  Write summary file (to the optional filename)\n");
+	exit(-1);
+}
+
+static void
+clar_parse_args(int argc, char **argv)
+{
+	int i;
+
+	/* Verify options before execute */
+	for (i = 1; i < argc; ++i) {
+		char *argument = argv[i];
+
+		if (argument[0] != '-' || argument[1] == '\0'
+		    || strchr("sixvqQtlr", argument[1]) == NULL) {
+			clar_usage(argv[0]);
+		}
+	}
+
+	for (i = 1; i < argc; ++i) {
+		char *argument = argv[i];
+
+		switch (argument[1]) {
+		case 's':
+		case 'i':
+		case 'x': { /* given suite name */
+			int offset = (argument[2] == '=') ? 3 : 2, found = 0;
+			char action = argument[1];
+			size_t j, arglen, suitelen, cmplen;
+
+			argument += offset;
+			arglen = strlen(argument);
+
+			if (arglen == 0)
+				clar_usage(argv[0]);
+
+			for (j = 0; j < _clar_suite_count; ++j) {
+				suitelen = strlen(_clar_suites[j].name);
+				cmplen = (arglen < suitelen) ? arglen : suitelen;
+
+				if (strncmp(argument, _clar_suites[j].name, cmplen) == 0) {
+					int exact = (arglen >= suitelen);
+
+					/* Do we have a real suite prefix separated by a
+					 * trailing '::' or just a matching substring? */
+					if (arglen > suitelen && (argument[suitelen] != ':'
+						    || argument[suitelen + 1] != ':'))
+					    continue;
+
+					++found;
+
+					if (!exact)
+						_clar.verbosity = MAX(_clar.verbosity, 1);
+
+					switch (action) {
+					case 's': {
+						struct clar_explicit *explicit =
+							calloc(1, sizeof(struct clar_explicit));
+						assert(explicit);
+
+						explicit->suite_idx = j;
+						explicit->filter = argument;
+
+						if (_clar.explicit == NULL)
+							_clar.explicit = explicit;
+
+						if (_clar.last_explicit != NULL)
+							_clar.last_explicit->next = explicit;
+
+						_clar_suites[j].enabled = 1;
+						_clar.last_explicit = explicit;
+						break;
+					}
+					case 'i': _clar_suites[j].enabled = 1; break;
+					case 'x': _clar_suites[j].enabled = 0; break;
+					}
+
+					if (exact)
+						break;
+				}
+			}
+
+			if (!found) {
+				clar_print_onabort("No suite matching '%s' found.\n", argument);
+				exit(-1);
+			}
+			break;
+		}
+
+		case 'q':
+			_clar.report_errors_only = 1;
+			break;
+
+		case 'Q':
+			_clar.exit_on_error = 1;
+			break;
+
+		case 't':
+			_clar.output_format = CL_OUTPUT_TAP;
+			break;
+
+		case 'l': {
+			size_t j;
+			printf("Test suites (use -s<name> to run just one):\n");
+			for (j = 0; j < _clar_suite_count; ++j)
+				printf(" %3d: %s\n", (int)j, _clar_suites[j].name);
+
+			exit(0);
+		}
+
+		case 'v':
+			_clar.verbosity++;
+			break;
+
+		case 'r':
+			_clar.write_summary = 1;
+			free(_clar.summary_filename);
+			_clar.summary_filename = *(argument + 2) ? strdup(argument + 2) : NULL;
+			break;
+
+		default:
+			assert(!"Unexpected commandline argument!");
+		}
+	}
+}
+
+void
+clar_test_init(int argc, char **argv)
+{
+	const char *summary_env;
+
+	if (argc > 1)
+		clar_parse_args(argc, argv);
+
+	clar_print_init(
+		(int)_clar_callback_count,
+		(int)_clar_suite_count,
+		""
+	);
+
+	if (!_clar.summary_filename &&
+	    (summary_env = getenv("CLAR_SUMMARY")) != NULL) {
+		_clar.write_summary = 1;
+		_clar.summary_filename = strdup(summary_env);
+	}
+
+	if (_clar.write_summary && !_clar.summary_filename)
+		_clar.summary_filename = strdup("summary.xml");
+
+	if (_clar.write_summary &&
+	    !(_clar.summary = clar_summary_init(_clar.summary_filename))) {
+		clar_print_onabort("Failed to open the summary file\n");
+		exit(-1);
+	}
+
+	if (clar_sandbox() < 0) {
+		clar_print_onabort("Failed to sandbox the test runner.\n");
+		exit(-1);
+	}
+}
+
+int
+clar_test_run(void)
+{
+	size_t i;
+	struct clar_explicit *explicit;
+
+	if (_clar.explicit) {
+		for (explicit = _clar.explicit; explicit; explicit = explicit->next)
+			clar_run_suite(&_clar_suites[explicit->suite_idx], explicit->filter);
+	} else {
+		for (i = 0; i < _clar_suite_count; ++i)
+			clar_run_suite(&_clar_suites[i], NULL);
+	}
+
+	return _clar.total_errors;
+}
+
+void
+clar_test_shutdown(void)
+{
+	struct clar_explicit *explicit, *explicit_next;
+	struct clar_report *report, *report_next;
+
+	clar_print_shutdown(
+		_clar.tests_ran,
+		(int)_clar_suite_count,
+		_clar.total_errors
+	);
+
+	clar_unsandbox();
+
+	if (_clar.write_summary && clar_summary_shutdown(_clar.summary) < 0) {
+		clar_print_onabort("Failed to write the summary file\n");
+		exit(-1);
+	}
+
+	for (explicit = _clar.explicit; explicit; explicit = explicit_next) {
+		explicit_next = explicit->next;
+		free(explicit);
+	}
+
+	for (report = _clar.reports; report; report = report_next) {
+		report_next = report->next;
+		free(report);
+	}
+
+	free(_clar.summary_filename);
+}
+
+int
+clar_test(int argc, char **argv)
+{
+	int errors;
+
+	clar_test_init(argc, argv);
+	errors = clar_test_run();
+	clar_test_shutdown();
+
+	return errors;
+}
+
+static void abort_test(void)
+{
+	if (!_clar.trampoline_enabled) {
+		clar_print_onabort(
+				"Fatal error: a cleanup method raised an exception.");
+		clar_report_errors(_clar.last_report);
+		exit(-1);
+	}
+
+	CL_TRACE(CL_TRACE__TEST__LONGJMP);
+	longjmp(_clar.trampoline, -1);
+}
+
+void clar__skip(void)
+{
+	_clar.last_report->status = CL_TEST_SKIP;
+	_clar.total_skipped++;
+	abort_test();
+}
+
+void clar__fail(
+	const char *file,
+	const char *function,
+	size_t line,
+	const char *error_msg,
+	const char *description,
+	int should_abort)
+{
+	struct clar_error *error = calloc(1, sizeof(struct clar_error));
+
+	if (_clar.last_report->errors == NULL)
+		_clar.last_report->errors = error;
+
+	if (_clar.last_report->last_error != NULL)
+		_clar.last_report->last_error->next = error;
+
+	_clar.last_report->last_error = error;
+
+	error->file = file;
+	error->function = function;
+	error->line_number = line;
+	error->error_msg = error_msg;
+
+	if (description != NULL)
+		error->description = strdup(description);
+
+	_clar.total_errors++;
+	_clar.last_report->status = CL_TEST_FAILURE;
+
+	if (should_abort)
+		abort_test();
+}
+
+void clar__assert(
+	int condition,
+	const char *file,
+	const char *function,
+	size_t line,
+	const char *error_msg,
+	const char *description,
+	int should_abort)
+{
+	if (condition)
+		return;
+
+	clar__fail(file, function, line, error_msg, description, should_abort);
+}
+
+void clar__assert_equal(
+	const char *file,
+	const char *function,
+	size_t line,
+	const char *err,
+	int should_abort,
+	const char *fmt,
+	...)
+{
+	va_list args;
+	char buf[4096];
+	int is_equal = 1;
+
+	va_start(args, fmt);
+
+	if (!strcmp("%s", fmt)) {
+		const char *s1 = va_arg(args, const char *);
+		const char *s2 = va_arg(args, const char *);
+		is_equal = (!s1 || !s2) ? (s1 == s2) : !strcmp(s1, s2);
+
+		if (!is_equal) {
+			if (s1 && s2) {
+				int pos;
+				for (pos = 0; s1[pos] == s2[pos] && s1[pos] && s2[pos]; ++pos)
+					/* find differing byte offset */;
+				p_snprintf(buf, sizeof(buf), "'%s' != '%s' (at byte %d)",
+					s1, s2, pos);
+			} else {
+				p_snprintf(buf, sizeof(buf), "'%s' != '%s'", s1, s2);
+			}
+		}
+	}
+	else if(!strcmp("%.*s", fmt)) {
+		const char *s1 = va_arg(args, const char *);
+		const char *s2 = va_arg(args, const char *);
+		int len = va_arg(args, int);
+		is_equal = (!s1 || !s2) ? (s1 == s2) : !strncmp(s1, s2, len);
+
+		if (!is_equal) {
+			if (s1 && s2) {
+				int pos;
+				for (pos = 0; s1[pos] == s2[pos] && pos < len; ++pos)
+					/* find differing byte offset */;
+				p_snprintf(buf, sizeof(buf), "'%.*s' != '%.*s' (at byte %d)",
+					len, s1, len, s2, pos);
+			} else {
+				p_snprintf(buf, sizeof(buf), "'%.*s' != '%.*s'", len, s1, len, s2);
+			}
+		}
+	}
+	else if (!strcmp("%ls", fmt)) {
+		const wchar_t *wcs1 = va_arg(args, const wchar_t *);
+		const wchar_t *wcs2 = va_arg(args, const wchar_t *);
+		is_equal = (!wcs1 || !wcs2) ? (wcs1 == wcs2) : !wcscmp(wcs1, wcs2);
+
+		if (!is_equal) {
+			if (wcs1 && wcs2) {
+				int pos;
+				for (pos = 0; wcs1[pos] == wcs2[pos] && wcs1[pos] && wcs2[pos]; ++pos)
+					/* find differing byte offset */;
+				p_snprintf(buf, sizeof(buf), "'%ls' != '%ls' (at byte %d)",
+					wcs1, wcs2, pos);
+			} else {
+				p_snprintf(buf, sizeof(buf), "'%ls' != '%ls'", wcs1, wcs2);
+			}
+		}
+	}
+	else if(!strcmp("%.*ls", fmt)) {
+		const wchar_t *wcs1 = va_arg(args, const wchar_t *);
+		const wchar_t *wcs2 = va_arg(args, const wchar_t *);
+		int len = va_arg(args, int);
+		is_equal = (!wcs1 || !wcs2) ? (wcs1 == wcs2) : !wcsncmp(wcs1, wcs2, len);
+
+		if (!is_equal) {
+			if (wcs1 && wcs2) {
+				int pos;
+				for (pos = 0; wcs1[pos] == wcs2[pos] && pos < len; ++pos)
+					/* find differing byte offset */;
+				p_snprintf(buf, sizeof(buf), "'%.*ls' != '%.*ls' (at byte %d)",
+					len, wcs1, len, wcs2, pos);
+			} else {
+				p_snprintf(buf, sizeof(buf), "'%.*ls' != '%.*ls'", len, wcs1, len, wcs2);
+			}
+		}
+	}
+	else if (!strcmp("%"PRIuZ, fmt) || !strcmp("%"PRIxZ, fmt)) {
+		size_t sz1 = va_arg(args, size_t), sz2 = va_arg(args, size_t);
+		is_equal = (sz1 == sz2);
+		if (!is_equal) {
+			int offset = p_snprintf(buf, sizeof(buf), fmt, sz1);
+			strncat(buf, " != ", sizeof(buf) - offset);
+			p_snprintf(buf + offset + 4, sizeof(buf) - offset - 4, fmt, sz2);
+		}
+	}
+	else if (!strcmp("%p", fmt)) {
+		void *p1 = va_arg(args, void *), *p2 = va_arg(args, void *);
+		is_equal = (p1 == p2);
+		if (!is_equal)
+			p_snprintf(buf, sizeof(buf), "%p != %p", p1, p2);
+	}
+	else {
+		int i1 = va_arg(args, int), i2 = va_arg(args, int);
+		is_equal = (i1 == i2);
+		if (!is_equal) {
+			int offset = p_snprintf(buf, sizeof(buf), fmt, i1);
+			strncat(buf, " != ", sizeof(buf) - offset);
+			p_snprintf(buf + offset + 4, sizeof(buf) - offset - 4, fmt, i2);
+		}
+	}
+
+	va_end(args);
+
+	if (!is_equal)
+		clar__fail(file, function, line, err, buf, should_abort);
+}
+
+void cl_set_cleanup(void (*cleanup)(void *), void *opaque)
+{
+	_clar.local_cleanup = cleanup;
+	_clar.local_cleanup_payload = opaque;
+}
+
+#include "clar/sandbox.h"
+#include "clar/fixtures.h"
+#include "clar/fs.h"
+#include "clar/print.h"
+#include "clar/summary.h"
diff --git a/t/unit-tests/clar/clar.h b/t/unit-tests/clar/clar.h
new file mode 100644
index 0000000000..8c22382bd5
--- /dev/null
+++ b/t/unit-tests/clar/clar.h
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) Vicent Marti. All rights reserved.
+ *
+ * This file is part of clar, distributed under the ISC license.
+ * For full terms see the included COPYING file.
+ */
+#ifndef __CLAR_TEST_H__
+#define __CLAR_TEST_H__
+
+#include <stdlib.h>
+
+enum cl_test_status {
+	CL_TEST_OK,
+	CL_TEST_FAILURE,
+	CL_TEST_SKIP,
+	CL_TEST_NOTRUN,
+};
+
+enum cl_output_format {
+	CL_OUTPUT_CLAP,
+	CL_OUTPUT_TAP,
+};
+
+/** Setup clar environment */
+void clar_test_init(int argc, char *argv[]);
+int clar_test_run(void);
+void clar_test_shutdown(void);
+
+/** One shot setup & run */
+int clar_test(int argc, char *argv[]);
+
+const char *clar_sandbox_path(void);
+
+void cl_set_cleanup(void (*cleanup)(void *), void *opaque);
+void cl_fs_cleanup(void);
+
+/**
+ * cl_trace_* is a hook to provide a simple global tracing
+ * mechanism.
+ *
+ * The goal here is to let main() provide clar-proper
+ * with a callback to optionally write log info for
+ * test operations into the same stream used by their
+ * actual tests.  This would let them print test names
+ * and maybe performance data as they choose.
+ *
+ * The goal is NOT to alter the flow of control or to
+ * override test selection/skipping.  (So the callback
+ * does not return a value.)
+ *
+ * The goal is NOT to duplicate the existing
+ * pass/fail/skip reporting.  (So the callback
+ * does not accept a status/errorcode argument.)
+ *
+ */
+typedef enum cl_trace_event {
+	CL_TRACE__SUITE_BEGIN,
+	CL_TRACE__SUITE_END,
+	CL_TRACE__TEST__BEGIN,
+	CL_TRACE__TEST__END,
+	CL_TRACE__TEST__RUN_BEGIN,
+	CL_TRACE__TEST__RUN_END,
+	CL_TRACE__TEST__LONGJMP,
+} cl_trace_event;
+
+typedef void (cl_trace_cb)(
+	cl_trace_event ev,
+	const char *suite_name,
+	const char *test_name,
+	void *payload);
+
+/**
+ * Register a callback into CLAR to send global trace events.
+ * Pass NULL to disable.
+ */
+void cl_trace_register(cl_trace_cb *cb, void *payload);
+
+
+#ifdef CLAR_FIXTURE_PATH
+const char *cl_fixture(const char *fixture_name);
+void cl_fixture_sandbox(const char *fixture_name);
+void cl_fixture_cleanup(const char *fixture_name);
+const char *cl_fixture_basename(const char *fixture_name);
+#endif
+
+/**
+ * Assertion macros with explicit error message
+ */
+#define cl_must_pass_(expr, desc) clar__assert((expr) >= 0, __FILE__, __func__, __LINE__, "Function call failed: " #expr, desc, 1)
+#define cl_must_fail_(expr, desc) clar__assert((expr) < 0, __FILE__, __func__, __LINE__, "Expected function call to fail: " #expr, desc, 1)
+#define cl_assert_(expr, desc) clar__assert((expr) != 0, __FILE__, __func__, __LINE__, "Expression is not true: " #expr, desc, 1)
+
+/**
+ * Check macros with explicit error message
+ */
+#define cl_check_pass_(expr, desc) clar__assert((expr) >= 0, __FILE__, __func__, __LINE__, "Function call failed: " #expr, desc, 0)
+#define cl_check_fail_(expr, desc) clar__assert((expr) < 0, __FILE__, __func__, __LINE__, "Expected function call to fail: " #expr, desc, 0)
+#define cl_check_(expr, desc) clar__assert((expr) != 0, __FILE__, __func__, __LINE__, "Expression is not true: " #expr, desc, 0)
+
+/**
+ * Assertion macros with no error message
+ */
+#define cl_must_pass(expr) cl_must_pass_(expr, NULL)
+#define cl_must_fail(expr) cl_must_fail_(expr, NULL)
+#define cl_assert(expr) cl_assert_(expr, NULL)
+
+/**
+ * Check macros with no error message
+ */
+#define cl_check_pass(expr) cl_check_pass_(expr, NULL)
+#define cl_check_fail(expr) cl_check_fail_(expr, NULL)
+#define cl_check(expr) cl_check_(expr, NULL)
+
+/**
+ * Forced failure/warning
+ */
+#define cl_fail(desc) clar__fail(__FILE__, __func__, __LINE__, "Test failed.", desc, 1)
+#define cl_warning(desc) clar__fail(__FILE__, __func__, __LINE__, "Warning during test execution:", desc, 0)
+
+#define cl_skip() clar__skip()
+
+/**
+ * Typed assertion macros
+ */
+#define cl_assert_equal_s(s1,s2) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #s1 " != " #s2, 1, "%s", (s1), (s2))
+#define cl_assert_equal_s_(s1,s2,note) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #s1 " != " #s2 " (" #note ")", 1, "%s", (s1), (s2))
+
+#define cl_assert_equal_wcs(wcs1,wcs2) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #wcs1 " != " #wcs2, 1, "%ls", (wcs1), (wcs2))
+#define cl_assert_equal_wcs_(wcs1,wcs2,note) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #wcs1 " != " #wcs2 " (" #note ")", 1, "%ls", (wcs1), (wcs2))
+
+#define cl_assert_equal_strn(s1,s2,len) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #s1 " != " #s2, 1, "%.*s", (s1), (s2), (int)(len))
+#define cl_assert_equal_strn_(s1,s2,len,note) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #s1 " != " #s2 " (" #note ")", 1, "%.*s", (s1), (s2), (int)(len))
+
+#define cl_assert_equal_wcsn(wcs1,wcs2,len) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #wcs1 " != " #wcs2, 1, "%.*ls", (wcs1), (wcs2), (int)(len))
+#define cl_assert_equal_wcsn_(wcs1,wcs2,len,note) clar__assert_equal(__FILE__,__func__,__LINE__,"String mismatch: " #wcs1 " != " #wcs2 " (" #note ")", 1, "%.*ls", (wcs1), (wcs2), (int)(len))
+
+#define cl_assert_equal_i(i1,i2) clar__assert_equal(__FILE__,__func__,__LINE__,#i1 " != " #i2, 1, "%d", (int)(i1), (int)(i2))
+#define cl_assert_equal_i_(i1,i2,note) clar__assert_equal(__FILE__,__func__,__LINE__,#i1 " != " #i2 " (" #note ")", 1, "%d", (i1), (i2))
+#define cl_assert_equal_i_fmt(i1,i2,fmt) clar__assert_equal(__FILE__,__func__,__LINE__,#i1 " != " #i2, 1, (fmt), (int)(i1), (int)(i2))
+
+#define cl_assert_equal_b(b1,b2) clar__assert_equal(__FILE__,__func__,__LINE__,#b1 " != " #b2, 1, "%d", (int)((b1) != 0),(int)((b2) != 0))
+
+#define cl_assert_equal_p(p1,p2) clar__assert_equal(__FILE__,__func__,__LINE__,"Pointer mismatch: " #p1 " != " #p2, 1, "%p", (p1), (p2))
+
+void clar__skip(void);
+
+void clar__fail(
+	const char *file,
+	const char *func,
+	size_t line,
+	const char *error,
+	const char *description,
+	int should_abort);
+
+void clar__assert(
+	int condition,
+	const char *file,
+	const char *func,
+	size_t line,
+	const char *error,
+	const char *description,
+	int should_abort);
+
+void clar__assert_equal(
+	const char *file,
+	const char *func,
+	size_t line,
+	const char *err,
+	int should_abort,
+	const char *fmt,
+	...);
+
+#endif
diff --git a/t/unit-tests/clar/clar/fixtures.h b/t/unit-tests/clar/clar/fixtures.h
new file mode 100644
index 0000000000..6ec6423484
--- /dev/null
+++ b/t/unit-tests/clar/clar/fixtures.h
@@ -0,0 +1,50 @@
+#ifdef CLAR_FIXTURE_PATH
+static const char *
+fixture_path(const char *base, const char *fixture_name)
+{
+	static char _path[4096];
+	size_t root_len;
+
+	root_len = strlen(base);
+	strncpy(_path, base, sizeof(_path));
+
+	if (_path[root_len - 1] != '/')
+		_path[root_len++] = '/';
+
+	if (fixture_name[0] == '/')
+		fixture_name++;
+
+	strncpy(_path + root_len,
+		fixture_name,
+		sizeof(_path) - root_len);
+
+	return _path;
+}
+
+const char *cl_fixture(const char *fixture_name)
+{
+	return fixture_path(CLAR_FIXTURE_PATH, fixture_name);
+}
+
+void cl_fixture_sandbox(const char *fixture_name)
+{
+	fs_copy(cl_fixture(fixture_name), _clar_path);
+}
+
+const char *cl_fixture_basename(const char *fixture_name)
+{
+	const char *p;
+
+	for (p = fixture_name; *p; p++) {
+		if (p[0] == '/' && p[1] && p[1] != '/')
+			fixture_name = p+1;
+	}
+
+	return fixture_name;
+}
+
+void cl_fixture_cleanup(const char *fixture_name)
+{
+	fs_rm(fixture_path(_clar_path, cl_fixture_basename(fixture_name)));
+}
+#endif
diff --git a/t/unit-tests/clar/clar/fs.h b/t/unit-tests/clar/clar/fs.h
new file mode 100644
index 0000000000..a6eda5e5dc
--- /dev/null
+++ b/t/unit-tests/clar/clar/fs.h
@@ -0,0 +1,522 @@
+/*
+ * By default, use a read/write loop to copy files on POSIX systems.
+ * On Linux, use sendfile by default as it's slightly faster.  On
+ * macOS, we avoid fcopyfile by default because it's slightly slower.
+ */
+#undef USE_FCOPYFILE
+#define USE_SENDFILE 1
+
+#ifdef _WIN32
+
+#ifdef CLAR_WIN32_LONGPATHS
+# define CLAR_MAX_PATH 4096
+#else
+# define CLAR_MAX_PATH MAX_PATH
+#endif
+
+#define RM_RETRY_COUNT	5
+#define RM_RETRY_DELAY	10
+
+#ifdef __MINGW32__
+
+/* These security-enhanced functions are not available
+ * in MinGW, so just use the vanilla ones */
+#define wcscpy_s(a, b, c) wcscpy((a), (c))
+#define wcscat_s(a, b, c) wcscat((a), (c))
+
+#endif /* __MINGW32__ */
+
+static int
+fs__dotordotdot(WCHAR *_tocheck)
+{
+	return _tocheck[0] == '.' &&
+		(_tocheck[1] == '\0' ||
+		 (_tocheck[1] == '.' && _tocheck[2] == '\0'));
+}
+
+static int
+fs_rmdir_rmdir(WCHAR *_wpath)
+{
+	unsigned retries = 1;
+
+	while (!RemoveDirectoryW(_wpath)) {
+		/* Only retry when we have retries remaining, and the
+		 * error was ERROR_DIR_NOT_EMPTY. */
+		if (retries++ > RM_RETRY_COUNT ||
+			ERROR_DIR_NOT_EMPTY != GetLastError())
+			return -1;
+
+		/* Give whatever has a handle to a child item some time
+		 * to release it before trying again */
+		Sleep(RM_RETRY_DELAY * retries * retries);
+	}
+
+	return 0;
+}
+
+static void translate_path(WCHAR *path, size_t path_size)
+{
+    size_t path_len, i;
+
+    if (wcsncmp(path, L"\\\\?\\", 4) == 0)
+	return;
+
+    path_len = wcslen(path);
+    cl_assert(path_size > path_len + 4);
+
+    for (i = path_len; i > 0; i--) {
+	WCHAR c = path[i - 1];
+
+	if (c == L'/')
+	    path[i + 3] = L'\\';
+	else
+	    path[i + 3] = path[i - 1];
+    }
+
+    path[0] = L'\\';
+    path[1] = L'\\';
+    path[2] = L'?';
+    path[3] = L'\\';
+    path[path_len + 4] = L'\0';
+}
+
+static void
+fs_rmdir_helper(WCHAR *_wsource)
+{
+	WCHAR buffer[CLAR_MAX_PATH];
+	HANDLE find_handle;
+	WIN32_FIND_DATAW find_data;
+	size_t buffer_prefix_len;
+
+	/* Set up the buffer and capture the length */
+	wcscpy_s(buffer, CLAR_MAX_PATH, _wsource);
+	translate_path(buffer, CLAR_MAX_PATH);
+	wcscat_s(buffer, CLAR_MAX_PATH, L"\\");
+	buffer_prefix_len = wcslen(buffer);
+
+	/* FindFirstFile needs a wildcard to match multiple items */
+	wcscat_s(buffer, CLAR_MAX_PATH, L"*");
+	find_handle = FindFirstFileW(buffer, &find_data);
+	cl_assert(INVALID_HANDLE_VALUE != find_handle);
+
+	do {
+		/* FindFirstFile/FindNextFile gives back . and ..
+		 * entries at the beginning */
+		if (fs__dotordotdot(find_data.cFileName))
+			continue;
+
+		wcscpy_s(buffer + buffer_prefix_len, CLAR_MAX_PATH - buffer_prefix_len, find_data.cFileName);
+
+		if (FILE_ATTRIBUTE_DIRECTORY & find_data.dwFileAttributes)
+			fs_rmdir_helper(buffer);
+		else {
+			/* If set, the +R bit must be cleared before deleting */
+			if (FILE_ATTRIBUTE_READONLY & find_data.dwFileAttributes)
+				cl_assert(SetFileAttributesW(buffer, find_data.dwFileAttributes & ~FILE_ATTRIBUTE_READONLY));
+
+			cl_assert(DeleteFileW(buffer));
+		}
+	}
+	while (FindNextFileW(find_handle, &find_data));
+
+	/* Ensure that we successfully completed the enumeration */
+	cl_assert(ERROR_NO_MORE_FILES == GetLastError());
+
+	/* Close the find handle */
+	FindClose(find_handle);
+
+	/* Now that the directory is empty, remove it */
+	cl_assert(0 == fs_rmdir_rmdir(_wsource));
+}
+
+static int
+fs_rm_wait(WCHAR *_wpath)
+{
+	unsigned retries = 1;
+	DWORD last_error;
+
+	do {
+		if (INVALID_FILE_ATTRIBUTES == GetFileAttributesW(_wpath))
+			last_error = GetLastError();
+		else
+			last_error = ERROR_SUCCESS;
+
+		/* Is the item gone? */
+		if (ERROR_FILE_NOT_FOUND == last_error ||
+			ERROR_PATH_NOT_FOUND == last_error)
+			return 0;
+
+		Sleep(RM_RETRY_DELAY * retries * retries);	
+	}
+	while (retries++ <= RM_RETRY_COUNT);
+
+	return -1;
+}
+
+static void
+fs_rm(const char *_source)
+{
+	WCHAR wsource[CLAR_MAX_PATH];
+	DWORD attrs;
+
+	/* The input path is UTF-8. Convert it to wide characters
+	 * for use with the Windows API */
+	cl_assert(MultiByteToWideChar(CP_UTF8,
+				MB_ERR_INVALID_CHARS,
+				_source,
+				-1, /* Indicates NULL termination */
+				wsource,
+				CLAR_MAX_PATH));
+
+	translate_path(wsource, CLAR_MAX_PATH);
+
+	/* Does the item exist? If not, we have no work to do */
+	attrs = GetFileAttributesW(wsource);
+
+	if (INVALID_FILE_ATTRIBUTES == attrs)
+		return;
+
+	if (FILE_ATTRIBUTE_DIRECTORY & attrs)
+		fs_rmdir_helper(wsource);
+	else {
+		/* The item is a file. Strip the +R bit */
+		if (FILE_ATTRIBUTE_READONLY & attrs)
+			cl_assert(SetFileAttributesW(wsource, attrs & ~FILE_ATTRIBUTE_READONLY));
+
+		cl_assert(DeleteFileW(wsource));
+	}
+
+	/* Wait for the DeleteFile or RemoveDirectory call to complete */
+	cl_assert(0 == fs_rm_wait(wsource));
+}
+
+static void
+fs_copydir_helper(WCHAR *_wsource, WCHAR *_wdest)
+{
+	WCHAR buf_source[CLAR_MAX_PATH], buf_dest[CLAR_MAX_PATH];
+	HANDLE find_handle;
+	WIN32_FIND_DATAW find_data;
+	size_t buf_source_prefix_len, buf_dest_prefix_len;
+
+	wcscpy_s(buf_source, CLAR_MAX_PATH, _wsource);
+	wcscat_s(buf_source, CLAR_MAX_PATH, L"\\");
+	translate_path(buf_source, CLAR_MAX_PATH);
+	buf_source_prefix_len = wcslen(buf_source);
+
+	wcscpy_s(buf_dest, CLAR_MAX_PATH, _wdest);
+	wcscat_s(buf_dest, CLAR_MAX_PATH, L"\\");
+	translate_path(buf_dest, CLAR_MAX_PATH);
+	buf_dest_prefix_len = wcslen(buf_dest);
+
+	/* Get an enumerator for the items in the source. */
+	wcscat_s(buf_source, CLAR_MAX_PATH, L"*");
+	find_handle = FindFirstFileW(buf_source, &find_data);
+	cl_assert(INVALID_HANDLE_VALUE != find_handle);
+
+	/* Create the target directory. */
+	cl_assert(CreateDirectoryW(_wdest, NULL));
+
+	do {
+		/* FindFirstFile/FindNextFile gives back . and ..
+		 * entries at the beginning */
+		if (fs__dotordotdot(find_data.cFileName))
+			continue;
+
+		wcscpy_s(buf_source + buf_source_prefix_len, CLAR_MAX_PATH - buf_source_prefix_len, find_data.cFileName);
+		wcscpy_s(buf_dest + buf_dest_prefix_len, CLAR_MAX_PATH - buf_dest_prefix_len, find_data.cFileName);
+
+		if (FILE_ATTRIBUTE_DIRECTORY & find_data.dwFileAttributes)
+			fs_copydir_helper(buf_source, buf_dest);
+		else
+			cl_assert(CopyFileW(buf_source, buf_dest, TRUE));
+	}
+	while (FindNextFileW(find_handle, &find_data));
+
+	/* Ensure that we successfully completed the enumeration */
+	cl_assert(ERROR_NO_MORE_FILES == GetLastError());
+
+	/* Close the find handle */
+	FindClose(find_handle);
+}
+
+static void
+fs_copy(const char *_source, const char *_dest)
+{
+	WCHAR wsource[CLAR_MAX_PATH], wdest[CLAR_MAX_PATH];
+	DWORD source_attrs, dest_attrs;
+	HANDLE find_handle;
+	WIN32_FIND_DATAW find_data;
+
+	/* The input paths are UTF-8. Convert them to wide characters
+	 * for use with the Windows API. */
+	cl_assert(MultiByteToWideChar(CP_UTF8,
+				MB_ERR_INVALID_CHARS,
+				_source,
+				-1,
+				wsource,
+				CLAR_MAX_PATH));
+
+	cl_assert(MultiByteToWideChar(CP_UTF8,
+				MB_ERR_INVALID_CHARS,
+				_dest,
+				-1,
+				wdest,
+				CLAR_MAX_PATH));
+
+	translate_path(wsource, CLAR_MAX_PATH);
+	translate_path(wdest, CLAR_MAX_PATH);
+
+	/* Check the source for existence */
+	source_attrs = GetFileAttributesW(wsource);
+	cl_assert(INVALID_FILE_ATTRIBUTES != source_attrs);
+
+	/* Check the target for existence */
+	dest_attrs = GetFileAttributesW(wdest);
+
+	if (INVALID_FILE_ATTRIBUTES != dest_attrs) {
+		/* Target exists; append last path part of source to target.
+		 * Use FindFirstFile to parse the path */
+		find_handle = FindFirstFileW(wsource, &find_data);
+		cl_assert(INVALID_HANDLE_VALUE != find_handle);
+		wcscat_s(wdest, CLAR_MAX_PATH, L"\\");
+		wcscat_s(wdest, CLAR_MAX_PATH, find_data.cFileName);
+		FindClose(find_handle);
+
+		/* Check the new target for existence */
+		cl_assert(INVALID_FILE_ATTRIBUTES == GetFileAttributesW(wdest));
+	}
+
+	if (FILE_ATTRIBUTE_DIRECTORY & source_attrs)
+		fs_copydir_helper(wsource, wdest);
+	else
+		cl_assert(CopyFileW(wsource, wdest, TRUE));
+}
+
+void
+cl_fs_cleanup(void)
+{
+#ifdef CLAR_FIXTURE_PATH
+	fs_rm(fixture_path(_clar_path, "*"));
+#endif
+}
+
+#else
+
+#include <errno.h>
+#include <string.h>
+#include <limits.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#if defined(__linux__)
+# include <sys/sendfile.h>
+#endif
+
+#if defined(__APPLE__)
+# include <copyfile.h>
+#endif
+
+static void basename_r(const char **out, int *out_len, const char *in)
+{
+	size_t in_len = strlen(in), start_pos;
+
+	for (in_len = strlen(in); in_len; in_len--) {
+		if (in[in_len - 1] != '/')
+			break;
+	}
+
+	for (start_pos = in_len; start_pos; start_pos--) {
+		if (in[start_pos - 1] == '/')
+			break;
+	}
+
+	cl_assert(in_len - start_pos < INT_MAX);
+
+	if (in_len - start_pos > 0) {
+		*out = &in[start_pos];
+		*out_len = (in_len - start_pos);
+	} else {
+		*out = "/";
+		*out_len = 1;
+	}
+}
+
+static char *joinpath(const char *dir, const char *base, int base_len)
+{
+	char *out;
+	int len;
+
+	if (base_len == -1) {
+		size_t bl = strlen(base);
+
+		cl_assert(bl < INT_MAX);
+		base_len = (int)bl;
+	}
+
+	len = strlen(dir) + base_len + 2;
+	cl_assert(len > 0);
+
+	cl_assert(out = malloc(len));
+	cl_assert(snprintf(out, len, "%s/%.*s", dir, base_len, base) < len);
+
+	return out;
+}
+
+static void
+fs_copydir_helper(const char *source, const char *dest, int dest_mode)
+{
+	DIR *source_dir;
+	struct dirent *d;
+
+	mkdir(dest, dest_mode);
+
+	cl_assert_(source_dir = opendir(source), "Could not open source dir");
+	while ((d = (errno = 0, readdir(source_dir))) != NULL) {
+		char *child;
+
+		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+			continue;
+
+		child = joinpath(source, d->d_name, -1);
+		fs_copy(child, dest);
+		free(child);
+	}
+
+	cl_assert_(errno == 0, "Failed to iterate source dir");
+
+	closedir(source_dir);
+}
+
+static void
+fs_copyfile_helper(const char *source, size_t source_len, const char *dest, int dest_mode)
+{
+	int in, out;
+
+	cl_must_pass((in = open(source, O_RDONLY)));
+	cl_must_pass((out = open(dest, O_WRONLY|O_CREAT|O_TRUNC, dest_mode)));
+
+#if USE_FCOPYFILE && defined(__APPLE__)
+	((void)(source_len)); /* unused */
+	cl_must_pass(fcopyfile(in, out, 0, COPYFILE_DATA));
+#elif USE_SENDFILE && defined(__linux__)
+	{
+		ssize_t ret = 0;
+
+		while (source_len && (ret = sendfile(out, in, NULL, source_len)) > 0) {
+			source_len -= (size_t)ret;
+		}
+		cl_assert(ret >= 0);
+	}
+#else
+	{
+		char buf[131072];
+		ssize_t ret;
+
+		((void)(source_len)); /* unused */
+
+		while ((ret = read(in, buf, sizeof(buf))) > 0) {
+			size_t len = (size_t)ret;
+
+			while (len && (ret = write(out, buf, len)) > 0) {
+				cl_assert(ret <= (ssize_t)len);
+				len -= ret;
+			}
+			cl_assert(ret >= 0);
+		}
+		cl_assert(ret == 0);
+	}
+#endif
+
+	close(in);
+	close(out);
+}
+
+static void
+fs_copy(const char *source, const char *_dest)
+{
+	char *dbuf = NULL;
+	const char *dest = NULL;
+	struct stat source_st, dest_st;
+
+	cl_must_pass_(lstat(source, &source_st), "Failed to stat copy source");
+
+	if (lstat(_dest, &dest_st) == 0) {
+		const char *base;
+		int base_len;
+
+		/* Target exists and is directory; append basename */
+		cl_assert(S_ISDIR(dest_st.st_mode));
+
+		basename_r(&base, &base_len, source);
+		cl_assert(base_len < INT_MAX);
+
+		dbuf = joinpath(_dest, base, base_len);
+		dest = dbuf;
+	} else if (errno != ENOENT) {
+		cl_fail("Cannot copy; cannot stat destination");
+	} else {
+		dest = _dest;
+	}
+
+	if (S_ISDIR(source_st.st_mode)) {
+		fs_copydir_helper(source, dest, source_st.st_mode);
+	} else {
+		fs_copyfile_helper(source, source_st.st_size, dest, source_st.st_mode);
+	}
+
+	free(dbuf);
+}
+
+static void
+fs_rmdir_helper(const char *path)
+{
+	DIR *dir;
+	struct dirent *d;
+
+	cl_assert_(dir = opendir(path), "Could not open dir");
+	while ((d = (errno = 0, readdir(dir))) != NULL) {
+		char *child;
+
+		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
+			continue;
+
+		child = joinpath(path, d->d_name, -1);
+		fs_rm(child);
+		free(child);
+	}
+
+	cl_assert_(errno == 0, "Failed to iterate source dir");
+	closedir(dir);
+
+	cl_must_pass_(rmdir(path), "Could not remove directory");
+}
+
+static void
+fs_rm(const char *path)
+{
+	struct stat st;
+
+	if (lstat(path, &st)) {
+		if (errno == ENOENT)
+			return;
+
+		cl_fail("Cannot copy; cannot stat destination");
+	}
+
+	if (S_ISDIR(st.st_mode)) {
+		fs_rmdir_helper(path);
+	} else {
+		cl_must_pass(unlink(path));
+	}
+}
+
+void
+cl_fs_cleanup(void)
+{
+	clar_unsandbox();
+	clar_sandbox();
+}
+#endif
diff --git a/t/unit-tests/clar/clar/print.h b/t/unit-tests/clar/clar/print.h
new file mode 100644
index 0000000000..c17e2f693b
--- /dev/null
+++ b/t/unit-tests/clar/clar/print.h
@@ -0,0 +1,211 @@
+/* clap: clar protocol, the traditional clar output format */
+
+static void clar_print_clap_init(int test_count, int suite_count, const char *suite_names)
+{
+	(void)test_count;
+	printf("Loaded %d suites: %s\n", (int)suite_count, suite_names);
+	printf("Started (test status codes: OK='.' FAILURE='F' SKIPPED='S')\n");
+}
+
+static void clar_print_clap_shutdown(int test_count, int suite_count, int error_count)
+{
+	(void)test_count;
+	(void)suite_count;
+	(void)error_count;
+
+	printf("\n\n");
+	clar_report_all();
+}
+
+static void clar_print_clap_error(int num, const struct clar_report *report, const struct clar_error *error)
+{
+	printf("  %d) Failure:\n", num);
+
+	printf("%s::%s [%s:%"PRIuZ"]\n",
+		report->suite,
+		report->test,
+		error->file,
+		error->line_number);
+
+	printf("  %s\n", error->error_msg);
+
+	if (error->description != NULL)
+		printf("  %s\n", error->description);
+
+	printf("\n");
+	fflush(stdout);
+}
+
+static void clar_print_clap_ontest(const char *suite_name, const char *test_name, int test_number, enum cl_test_status status)
+{
+	(void)test_name;
+	(void)test_number;
+
+	if (_clar.verbosity > 1) {
+		printf("%s::%s: ", suite_name, test_name);
+
+		switch (status) {
+		case CL_TEST_OK: printf("ok\n"); break;
+		case CL_TEST_FAILURE: printf("fail\n"); break;
+		case CL_TEST_SKIP: printf("skipped"); break;
+		case CL_TEST_NOTRUN: printf("notrun"); break;
+		}
+	} else {
+		switch (status) {
+		case CL_TEST_OK: printf("."); break;
+		case CL_TEST_FAILURE: printf("F"); break;
+		case CL_TEST_SKIP: printf("S"); break;
+		case CL_TEST_NOTRUN: printf("N"); break;
+		}
+
+		fflush(stdout);
+	}
+}
+
+static void clar_print_clap_onsuite(const char *suite_name, int suite_index)
+{
+	if (_clar.verbosity == 1)
+		printf("\n%s", suite_name);
+
+	(void)suite_index;
+}
+
+static void clar_print_clap_onabort(const char *fmt, va_list arg)
+{
+	vfprintf(stderr, fmt, arg);
+}
+
+/* tap: test anywhere protocol format */
+
+static void clar_print_tap_init(int test_count, int suite_count, const char *suite_names)
+{
+	(void)test_count;
+	(void)suite_count;
+	(void)suite_names;
+	printf("TAP version 13\n");
+}
+
+static void clar_print_tap_shutdown(int test_count, int suite_count, int error_count)
+{
+	(void)suite_count;
+	(void)error_count;
+
+	printf("1..%d\n", test_count);
+}
+
+static void clar_print_tap_error(int num, const struct clar_report *report, const struct clar_error *error)
+{
+	(void)num;
+	(void)report;
+	(void)error;
+}
+
+static void print_escaped(const char *str)
+{
+	char *c;
+
+	while ((c = strchr(str, '\'')) != NULL) {
+		printf("%.*s", (int)(c - str), str);
+		printf("''");
+		str = c + 1;
+	}
+
+	printf("%s", str);
+}
+
+static void clar_print_tap_ontest(const char *suite_name, const char *test_name, int test_number, enum cl_test_status status)
+{
+	const struct clar_error *error = _clar.last_report->errors;
+
+	(void)test_name;
+	(void)test_number;
+
+	switch(status) {
+	case CL_TEST_OK:
+		printf("ok %d - %s::%s\n", test_number, suite_name, test_name);
+		break;
+	case CL_TEST_FAILURE:
+		printf("not ok %d - %s::%s\n", test_number, suite_name, test_name);
+
+		printf("    ---\n");
+		printf("    reason: |\n");
+		printf("      %s\n", error->error_msg);
+
+		if (error->description)
+			printf("      %s\n", error->description);
+
+		printf("    at:\n");
+		printf("      file: '"); print_escaped(error->file); printf("'\n");
+		printf("      line: %" PRIuZ "\n", error->line_number);
+		printf("      function: '%s'\n", error->function);
+		printf("    ---\n");
+
+		break;
+	case CL_TEST_SKIP:
+	case CL_TEST_NOTRUN:
+		printf("ok %d - # SKIP %s::%s\n", test_number, suite_name, test_name);
+		break;
+	}
+
+	fflush(stdout);
+}
+
+static void clar_print_tap_onsuite(const char *suite_name, int suite_index)
+{
+	printf("# start of suite %d: %s\n", suite_index, suite_name);
+}
+
+static void clar_print_tap_onabort(const char *fmt, va_list arg)
+{
+	printf("Bail out! ");
+	vprintf(fmt, arg);
+	fflush(stdout);
+}
+
+/* indirection between protocol output selection */
+
+#define PRINT(FN, ...) do { \
+		switch (_clar.output_format) { \
+			case CL_OUTPUT_CLAP: \
+				clar_print_clap_##FN (__VA_ARGS__); \
+				break; \
+			case CL_OUTPUT_TAP: \
+				clar_print_tap_##FN (__VA_ARGS__); \
+				break; \
+			default: \
+				abort(); \
+		} \
+	} while (0)
+
+static void clar_print_init(int test_count, int suite_count, const char *suite_names)
+{
+	PRINT(init, test_count, suite_count, suite_names);
+}
+
+static void clar_print_shutdown(int test_count, int suite_count, int error_count)
+{
+	PRINT(shutdown, test_count, suite_count, error_count);
+}
+
+static void clar_print_error(int num, const struct clar_report *report, const struct clar_error *error)
+{
+	PRINT(error, num, report, error);
+}
+
+static void clar_print_ontest(const char *suite_name, const char *test_name, int test_number, enum cl_test_status status)
+{
+	PRINT(ontest, suite_name, test_name, test_number, status);
+}
+
+static void clar_print_onsuite(const char *suite_name, int suite_index)
+{
+	PRINT(onsuite, suite_name, suite_index);
+}
+
+static void clar_print_onabort(const char *msg, ...)
+{
+	va_list argp;
+	va_start(argp, msg);
+	PRINT(onabort, msg, argp);
+	va_end(argp);
+}
diff --git a/t/unit-tests/clar/clar/sandbox.h b/t/unit-tests/clar/clar/sandbox.h
new file mode 100644
index 0000000000..0ba1479620
--- /dev/null
+++ b/t/unit-tests/clar/clar/sandbox.h
@@ -0,0 +1,154 @@
+#ifdef __APPLE__
+#include <sys/syslimits.h>
+#endif
+
+static char _clar_path[4096 + 1];
+
+static int
+is_valid_tmp_path(const char *path)
+{
+	STAT_T st;
+
+	if (stat(path, &st) != 0)
+		return 0;
+
+	if (!S_ISDIR(st.st_mode))
+		return 0;
+
+	return (access(path, W_OK) == 0);
+}
+
+static int
+find_tmp_path(char *buffer, size_t length)
+{
+#ifndef _WIN32
+	static const size_t var_count = 5;
+	static const char *env_vars[] = {
+		"CLAR_TMP", "TMPDIR", "TMP", "TEMP", "USERPROFILE"
+ 	};
+
+ 	size_t i;
+
+	for (i = 0; i < var_count; ++i) {
+		const char *env = getenv(env_vars[i]);
+		if (!env)
+			continue;
+
+		if (is_valid_tmp_path(env)) {
+#ifdef __APPLE__
+			if (length >= PATH_MAX && realpath(env, buffer) != NULL)
+				return 0;
+#endif
+			strncpy(buffer, env, length - 1);
+			buffer[length - 1] = '\0';
+			return 0;
+		}
+	}
+
+	/* If the environment doesn't say anything, try to use /tmp */
+	if (is_valid_tmp_path("/tmp")) {
+#ifdef __APPLE__
+		if (length >= PATH_MAX && realpath("/tmp", buffer) != NULL)
+			return 0;
+#endif
+		strncpy(buffer, "/tmp", length - 1);
+		buffer[length - 1] = '\0';
+		return 0;
+	}
+
+#else
+	DWORD env_len = GetEnvironmentVariable("CLAR_TMP", buffer, (DWORD)length);
+	if (env_len > 0 && env_len < (DWORD)length)
+		return 0;
+
+	if (GetTempPath((DWORD)length, buffer))
+		return 0;
+#endif
+
+	/* This system doesn't like us, try to use the current directory */
+	if (is_valid_tmp_path(".")) {
+		strncpy(buffer, ".", length - 1);
+		buffer[length - 1] = '\0';
+		return 0;
+	}
+
+	return -1;
+}
+
+static void clar_unsandbox(void)
+{
+	if (_clar_path[0] == '\0')
+		return;
+
+	cl_must_pass(chdir(".."));
+
+	fs_rm(_clar_path);
+}
+
+static int build_sandbox_path(void)
+{
+#ifdef CLAR_TMPDIR
+	const char path_tail[] = CLAR_TMPDIR "_XXXXXX";
+#else
+	const char path_tail[] = "clar_tmp_XXXXXX";
+#endif
+
+	size_t len;
+
+	if (find_tmp_path(_clar_path, sizeof(_clar_path)) < 0)
+		return -1;
+
+	len = strlen(_clar_path);
+
+#ifdef _WIN32
+	{ /* normalize path to POSIX forward slashes */
+		size_t i;
+		for (i = 0; i < len; ++i) {
+			if (_clar_path[i] == '\\')
+				_clar_path[i] = '/';
+		}
+	}
+#endif
+
+	if (_clar_path[len - 1] != '/') {
+		_clar_path[len++] = '/';
+	}
+
+	strncpy(_clar_path + len, path_tail, sizeof(_clar_path) - len);
+
+#if defined(__MINGW32__)
+	if (_mktemp(_clar_path) == NULL)
+		return -1;
+
+	if (mkdir(_clar_path, 0700) != 0)
+		return -1;
+#elif defined(_WIN32)
+	if (_mktemp_s(_clar_path, sizeof(_clar_path)) != 0)
+		return -1;
+
+	if (mkdir(_clar_path, 0700) != 0)
+		return -1;
+#else
+	if (mkdtemp(_clar_path) == NULL)
+		return -1;
+#endif
+
+	return 0;
+}
+
+static int clar_sandbox(void)
+{
+	if (_clar_path[0] == '\0' && build_sandbox_path() < 0)
+		return -1;
+
+	if (chdir(_clar_path) != 0)
+		return -1;
+
+	return 0;
+}
+
+const char *clar_sandbox_path(void)
+{
+	return _clar_path;
+}
+
diff --git a/t/unit-tests/clar/clar/summary.h b/t/unit-tests/clar/clar/summary.h
new file mode 100644
index 0000000000..4dd352e28b
--- /dev/null
+++ b/t/unit-tests/clar/clar/summary.h
@@ -0,0 +1,143 @@
+
+#include <stdio.h>
+#include <time.h>
+
+static int clar_summary_close_tag(
+    struct clar_summary *summary, const char *tag, int indent)
+{
+	const char *indt;
+
+	if (indent == 0) indt = "";
+	else if (indent == 1) indt = "\t";
+	else indt = "\t\t";
+
+	return fprintf(summary->fp, "%s</%s>\n", indt, tag);
+}
+
+static int clar_summary_testsuites(struct clar_summary *summary)
+{
+	return fprintf(summary->fp, "<testsuites>\n");
+}
+
+static int clar_summary_testsuite(struct clar_summary *summary,
+    int idn, const char *name, time_t timestamp,
+    int test_count, int fail_count, int error_count)
+{
+	struct tm *tm = localtime(&timestamp);
+	char iso_dt[20];
+
+	if (strftime(iso_dt, sizeof(iso_dt), "%Y-%m-%dT%H:%M:%S", tm) == 0)
+		return -1;
+
+	return fprintf(summary->fp, "\t<testsuite"
+		       " id=\"%d\""
+		       " name=\"%s\""
+		       " hostname=\"localhost\""
+		       " timestamp=\"%s\""
+		       " tests=\"%d\""
+		       " failures=\"%d\""
+		       " errors=\"%d\">\n",
+		       idn, name, iso_dt, test_count, fail_count, error_count);
+}
+
+static int clar_summary_testcase(struct clar_summary *summary,
+    const char *name, const char *classname, double elapsed)
+{
+	return fprintf(summary->fp,
+	    "\t\t<testcase name=\"%s\" classname=\"%s\" time=\"%.2f\">\n",
+		name, classname, elapsed);
+}
+
+static int clar_summary_failure(struct clar_summary *summary,
+    const char *type, const char *message, const char *desc)
+{
+	return fprintf(summary->fp,
+	    "\t\t\t<failure type=\"%s\"><![CDATA[%s\n%s]]></failure>\n",
+	    type, message, desc);
+}
+
+static int clar_summary_skipped(struct clar_summary *summary)
+{
+	return fprintf(summary->fp, "\t\t\t<skipped />\n");
+}
+
+struct clar_summary *clar_summary_init(const char *filename)
+{
+	struct clar_summary *summary;
+	FILE *fp;
+
+	if ((fp = fopen(filename, "w")) == NULL) {
+		perror("fopen");
+		return NULL;
+	}
+
+	if ((summary = malloc(sizeof(struct clar_summary))) == NULL) {
+		perror("malloc");
+		fclose(fp);
+		return NULL;
+	}
+
+	summary->filename = filename;
+	summary->fp = fp;
+
+	return summary;
+}
+
+int clar_summary_shutdown(struct clar_summary *summary)
+{
+	struct clar_report *report;
+	const char *last_suite = NULL;
+
+	if (clar_summary_testsuites(summary) < 0)
+		goto on_error;
+
+	report = _clar.reports;
+	while (report != NULL) {
+		struct clar_error *error = report->errors;
+
+		if (last_suite == NULL || strcmp(last_suite, report->suite) != 0) {
+			if (clar_summary_testsuite(summary, 0, report->suite,
+			    report->start, _clar.tests_ran, _clar.total_errors, 0) < 0)
+				goto on_error;
+		}
+
+		last_suite = report->suite;
+
+		clar_summary_testcase(summary, report->test, report->suite, report->elapsed);
+
+		while (error != NULL) {
+			if (clar_summary_failure(summary, "assert",
+			    error->error_msg, error->description) < 0)
+				goto on_error;
+
+			error = error->next;
+		}
+
+		if (report->status == CL_TEST_SKIP)
+			clar_summary_skipped(summary);
+
+		if (clar_summary_close_tag(summary, "testcase", 2) < 0)
+			goto on_error;
+
+		report = report->next;
+
+		if (!report || strcmp(last_suite, report->suite) != 0) {
+			if (clar_summary_close_tag(summary, "testsuite", 1) < 0)
+				goto on_error;
+		}
+	}
+
+	if (clar_summary_close_tag(summary, "testsuites", 0) < 0 ||
+	    fclose(summary->fp) != 0)
+		goto on_error;
+
+	printf("written summary file to %s\n", summary->filename);
+
+	free(summary);
+	return 0;
+
+on_error:
+	fclose(summary->fp);
+	free(summary);
+	return -1;
+}
diff --git a/t/unit-tests/clar/generate.py b/t/unit-tests/clar/generate.py
new file mode 100755
index 0000000000..931b4d60d9
--- /dev/null
+++ b/t/unit-tests/clar/generate.py
@@ -0,0 +1,267 @@
+#!/usr/bin/env python
+#
+# Copyright (c) Vicent Marti. All rights reserved.
+#
+# This file is part of clar, distributed under the ISC license.
+# For full terms see the included COPYING file.
+#
+
+from __future__ import with_statement
+from string import Template
+import re, fnmatch, os, sys, codecs, pickle
+
+class Module(object):
+    class Template(object):
+        def __init__(self, module):
+            self.module = module
+
+        def _render_callback(self, cb):
+            if not cb:
+                return '    { NULL, NULL }'
+            return '    { "%s", &%s }' % (cb['short_name'], cb['symbol'])
+
+    class DeclarationTemplate(Template):
+        def render(self):
+            out = "\n".join("extern %s;" % cb['declaration'] for cb in self.module.callbacks) + "\n"
+
+            for initializer in self.module.initializers:
+                out += "extern %s;\n" % initializer['declaration']
+
+            if self.module.cleanup:
+                out += "extern %s;\n" % self.module.cleanup['declaration']
+
+            return out
+
+    class CallbacksTemplate(Template):
+        def render(self):
+            out = "static const struct clar_func _clar_cb_%s[] = {\n" % self.module.name
+            out += ",\n".join(self._render_callback(cb) for cb in self.module.callbacks)
+            out += "\n};\n"
+            return out
+
+    class InfoTemplate(Template):
+        def render(self):
+            templates = []
+
+            initializers = self.module.initializers
+            if len(initializers) == 0:
+                initializers = [ None ]
+
+            for initializer in initializers:
+                name = self.module.clean_name()
+                if initializer and initializer['short_name'].startswith('initialize_'):
+                    variant = initializer['short_name'][len('initialize_'):]
+                    name += " (%s)" % variant.replace('_', ' ')
+
+                template = Template(
+            r"""
+    {
+        "${clean_name}",
+    ${initialize},
+    ${cleanup},
+        ${cb_ptr}, ${cb_count}, ${enabled}
+    }"""
+                ).substitute(
+                    clean_name = name,
+                    initialize = self._render_callback(initializer),
+                    cleanup = self._render_callback(self.module.cleanup),
+                    cb_ptr = "_clar_cb_%s" % self.module.name,
+                    cb_count = len(self.module.callbacks),
+                    enabled = int(self.module.enabled)
+                )
+                templates.append(template)
+
+            return ','.join(templates)
+
+    def __init__(self, name):
+        self.name = name
+
+        self.mtime = None
+        self.enabled = True
+        self.modified = False
+
+    def clean_name(self):
+        return self.name.replace("_", "::")
+
+    def _skip_comments(self, text):
+        SKIP_COMMENTS_REGEX = re.compile(
+            r'//.*?$|/\*.*?\*/|\'(?:\\.|[^\\\'])*\'|"(?:\\.|[^\\"])*"',
+            re.DOTALL | re.MULTILINE)
+
+        def _replacer(match):
+            s = match.group(0)
+            return "" if s.startswith('/') else s
+
+        return re.sub(SKIP_COMMENTS_REGEX, _replacer, text)
+
+    def parse(self, contents):
+        TEST_FUNC_REGEX = r"^(void\s+(test_%s__(\w+))\s*\(\s*void\s*\))\s*\{"
+
+        contents = self._skip_comments(contents)
+        regex = re.compile(TEST_FUNC_REGEX % self.name, re.MULTILINE)
+
+        self.callbacks = []
+        self.initializers = []
+        self.cleanup = None
+
+        for (declaration, symbol, short_name) in regex.findall(contents):
+            data = {
+                "short_name" : short_name,
+                "declaration" : declaration,
+                "symbol" : symbol
+            }
+
+            if short_name.startswith('initialize'):
+                self.initializers.append(data)
+            elif short_name == 'cleanup':
+                self.cleanup = data
+            else:
+                self.callbacks.append(data)
+
+        return self.callbacks != []
+
+    def refresh(self, path):
+        self.modified = False
+
+        try:
+            st = os.stat(path)
+
+            # Not modified
+            if st.st_mtime == self.mtime:
+                return True
+
+            self.modified = True
+            self.mtime = st.st_mtime
+
+            with codecs.open(path, encoding='utf-8') as fp:
+                raw_content = fp.read()
+
+        except IOError:
+            return False
+
+        return self.parse(raw_content)
+
+class TestSuite(object):
+
+    def __init__(self, path, output):
+        self.path = path
+        self.output = output
+
+    def should_generate(self, path):
+        if not os.path.isfile(path):
+            return True
+
+        if any(module.modified for module in self.modules.values()):
+            return True
+
+        return False
+
+    def find_modules(self):
+        modules = []
+        for root, _, files in os.walk(self.path):
+            module_root = root[len(self.path):]
+            module_root = [c for c in module_root.split(os.sep) if c]
+
+            tests_in_module = fnmatch.filter(files, "*.c")
+
+            for test_file in tests_in_module:
+                full_path = os.path.join(root, test_file)
+                module_name = "_".join(module_root + [test_file[:-2]]).replace("-", "_")
+
+                modules.append((full_path, module_name))
+
+        return modules
+
+    def load_cache(self):
+        path = os.path.join(self.output, '.clarcache')
+        cache = {}
+
+        try:
+            fp = open(path, 'rb')
+            cache = pickle.load(fp)
+            fp.close()
+        except (IOError, ValueError):
+            pass
+
+        return cache
+
+    def save_cache(self):
+        path = os.path.join(self.output, '.clarcache')
+        with open(path, 'wb') as cache:
+            pickle.dump(self.modules, cache)
+
+    def load(self, force = False):
+        module_data = self.find_modules()
+        self.modules = {} if force else self.load_cache()
+
+        for path, name in module_data:
+            if name not in self.modules:
+                self.modules[name] = Module(name)
+
+            if not self.modules[name].refresh(path):
+                del self.modules[name]
+
+    def disable(self, excluded):
+        for exclude in excluded:
+            for module in self.modules.values():
+                name = module.clean_name()
+                if name.startswith(exclude):
+                    module.enabled = False
+                    module.modified = True
+
+    def suite_count(self):
+        return sum(max(1, len(m.initializers)) for m in self.modules.values())
+
+    def callback_count(self):
+        return sum(len(module.callbacks) for module in self.modules.values())
+
+    def write(self):
+        output = os.path.join(self.output, 'clar.suite')
+
+        if not self.should_generate(output):
+            return False
+
+        with open(output, 'w') as data:
+            modules = sorted(self.modules.values(), key=lambda module: module.name)
+
+            for module in modules:
+                t = Module.DeclarationTemplate(module)
+                data.write(t.render())
+
+            for module in modules:
+                t = Module.CallbacksTemplate(module)
+                data.write(t.render())
+
+            suites = "static struct clar_suite _clar_suites[] = {" + ','.join(
+                Module.InfoTemplate(module).render() for module in modules
+            ) + "\n};\n"
+
+            data.write(suites)
+
+            data.write("static const size_t _clar_suite_count = %d;\n" % self.suite_count())
+            data.write("static const size_t _clar_callback_count = %d;\n" % self.callback_count())
+
+        self.save_cache()
+        return True
+
+if __name__ == '__main__':
+    from optparse import OptionParser
+
+    parser = OptionParser()
+    parser.add_option('-f', '--force', action="store_true", dest='force', default=False)
+    parser.add_option('-x', '--exclude', dest='excluded', action='append', default=[])
+    parser.add_option('-o', '--output', dest='output')
+
+    options, args = parser.parse_args()
+    if len(args) > 1:
+        print("More than one path given")
+        sys.exit(1)
+
+    path = args.pop() if args else '.'
+    output = options.output or path
+    suite = TestSuite(path, output)
+    suite.load(options.force)
+    suite.disable(options.excluded)
+    if suite.write():
+        print("Written `clar.suite` (%d tests in %d suites)" % (suite.callback_count(), suite.suite_count()))
+
diff --git a/t/unit-tests/clar/test/.gitignore b/t/unit-tests/clar/test/.gitignore
new file mode 100644
index 0000000000..3e8ae0a3a5
--- /dev/null
+++ b/t/unit-tests/clar/test/.gitignore
@@ -0,0 +1,5 @@
+clar.suite
+.clarcache
+clar_test
+*.o
+
diff --git a/t/unit-tests/clar/test/Makefile b/t/unit-tests/clar/test/Makefile
new file mode 100644
index 0000000000..93c6b2ad32
--- /dev/null
+++ b/t/unit-tests/clar/test/Makefile
@@ -0,0 +1,39 @@
+#
+# Copyright (c) Vicent Marti. All rights reserved.
+#
+# This file is part of clar, distributed under the ISC license.
+# For full terms see the included COPYING file.
+#
+
+#
+# Set up the path to the clar sources and to the fixtures directory
+#
+# The fixture path needs to be an absolute path so it can be used
+# even after we have chdir'ed into the test directory while testing.
+#
+CURRENT_MAKEFILE  := $(word $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST))
+TEST_DIRECTORY    := $(abspath $(dir $(CURRENT_MAKEFILE)))
+CLAR_PATH         := $(dir $(TEST_DIRECTORY))
+CLAR_FIXTURE_PATH := $(TEST_DIRECTORY)/resources/
+
+CFLAGS=-g -I.. -I. -Wall -DCLAR_FIXTURE_PATH=\"$(CLAR_FIXTURE_PATH)\"
+
+.PHONY: clean
+
+# list the objects that go into our test
+objects = main.o sample.o
+
+# build the test executable itself
+clar_test: $(objects) clar_test.h clar.suite $(CLAR_PATH)clar.c
+	$(CC) $(CFLAGS) -o $@ "$(CLAR_PATH)clar.c" $(objects)
+
+# test object files depend on clar macros
+$(objects) : $(CLAR_PATH)clar.h
+
+# build the clar.suite file of test metadata
+clar.suite:
+	python "$(CLAR_PATH)generate.py" .
+
+# remove all generated files
+clean:
+	$(RM) -rf *.o clar.suite .clarcache clar_test clar_test.dSYM
diff --git a/t/unit-tests/clar/test/clar_test.h b/t/unit-tests/clar/test/clar_test.h
new file mode 100644
index 0000000000..0fcaa639aa
--- /dev/null
+++ b/t/unit-tests/clar/test/clar_test.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) Vicent Marti. All rights reserved.
+ *
+ * This file is part of clar, distributed under the ISC license.
+ * For full terms see the included COPYING file.
+ */
+#ifndef __CLAR_TEST__
+#define __CLAR_TEST__
+
+/* Import the standard clar helper functions */
+#include "clar.h"
+
+/* Your custom shared includes / defines here */
+extern int global_test_counter;
+
+#endif
diff --git a/t/unit-tests/clar/test/main.c b/t/unit-tests/clar/test/main.c
new file mode 100644
index 0000000000..59e56ad255
--- /dev/null
+++ b/t/unit-tests/clar/test/main.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) Vicent Marti. All rights reserved.
+ *
+ * This file is part of clar, distributed under the ISC license.
+ * For full terms see the included COPYING file.
+ */
+
+#include "clar_test.h"
+
+/*
+ * Sample main() for clar tests.
+ *
+ * You should write your own main routine for clar tests that does specific
+ * setup and teardown as necessary for your application.  The only required
+ * line is the call to `clar_test(argc, argv)`, which will execute the test
+ * suite.  If you want to check the return value of the test application,
+ * your main() should return the same value returned by clar_test().
+ */
+
+int global_test_counter = 0;
+
+#ifdef _WIN32
+int __cdecl main(int argc, char *argv[])
+#else
+int main(int argc, char *argv[])
+#endif
+{
+	int ret;
+
+	/* Your custom initialization here */
+	global_test_counter = 0;
+
+	/* Run the test suite */
+	ret = clar_test(argc, argv);
+
+	/* Your custom cleanup here */
+	cl_assert_equal_i(8, global_test_counter);
+
+	return ret;
+}
diff --git a/t/unit-tests/clar/test/main.c.sample b/t/unit-tests/clar/test/main.c.sample
new file mode 100644
index 0000000000..a4d91b72fa
--- /dev/null
+++ b/t/unit-tests/clar/test/main.c.sample
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) Vicent Marti. All rights reserved.
+ *
+ * This file is part of clar, distributed under the ISC license.
+ * For full terms see the included COPYING file.
+ */
+
+#include "clar_test.h"
+
+/*
+ * Minimal main() for clar tests.
+ *
+ * Modify this with any application specific setup or teardown that you need.
+ * The only required line is the call to `clar_test(argc, argv)`, which will
+ * execute the test suite.  If you want to check the return value of the test
+ * application, main() should return the same value returned by clar_test().
+ */
+
+#ifdef _WIN32
+int __cdecl main(int argc, char *argv[])
+#else
+int main(int argc, char *argv[])
+#endif
+{
+	/* Run the test suite */
+	return clar_test(argc, argv);
+}
diff --git a/t/unit-tests/clar/test/resources/test/file b/t/unit-tests/clar/test/resources/test/file
new file mode 100644
index 0000000000..220f4aa98a
--- /dev/null
+++ b/t/unit-tests/clar/test/resources/test/file
@@ -0,0 +1 @@
+File
diff --git a/t/unit-tests/clar/test/sample.c b/t/unit-tests/clar/test/sample.c
new file mode 100644
index 0000000000..faa1209262
--- /dev/null
+++ b/t/unit-tests/clar/test/sample.c
@@ -0,0 +1,84 @@
+#include "clar_test.h"
+#include <sys/stat.h>
+
+static int file_size(const char *filename)
+{
+	struct stat st;
+
+	if (stat(filename, &st) == 0)
+		return (int)st.st_size;
+	return -1;
+}
+
+void test_sample__initialize(void)
+{
+	global_test_counter++;
+}
+
+void test_sample__cleanup(void)
+{
+	cl_fixture_cleanup("test");
+
+	cl_assert(file_size("test/file") == -1);
+}
+
+void test_sample__1(void)
+{
+	cl_assert(1);
+	cl_must_pass(0);  /* 0 == success */
+	cl_must_fail(-1); /* <0 == failure */
+	cl_must_pass(-1); /* demonstrate a failing call */
+}
+
+void test_sample__2(void)
+{
+	cl_fixture_sandbox("test");
+
+	cl_assert(file_size("test/nonexistent") == -1);
+	cl_assert(file_size("test/file") > 0);
+	cl_assert(100 == 101);
+}
+
+void test_sample__strings(void)
+{
+	const char *actual = "expected";
+	cl_assert_equal_s("expected", actual);
+	cl_assert_equal_s_("expected", actual, "second try with annotation");
+	cl_assert_equal_s_("mismatched", actual, "this one fails");
+}
+
+void test_sample__strings_with_length(void)
+{
+	const char *actual = "expected";
+	cl_assert_equal_strn("expected_", actual, 8);
+	cl_assert_equal_strn("exactly", actual, 2);
+	cl_assert_equal_strn_("expected_", actual, 8, "with annotation");
+	cl_assert_equal_strn_("exactly", actual, 3, "this one fails");
+}
+
+void test_sample__int(void)
+{
+	int value = 100;
+	cl_assert_equal_i(100, value);
+	cl_assert_equal_i_(101, value, "extra note on failing test");
+}
+
+void test_sample__int_fmt(void)
+{
+	int value = 100;
+	cl_assert_equal_i_fmt(022, value, "%04o");
+}
+
+void test_sample__bool(void)
+{
+	int value = 100;
+	cl_assert_equal_b(1, value);       /* test equality as booleans */
+	cl_assert_equal_b(0, value);
+}
+
+void test_sample__ptr(void)
+{
+	const char *actual = "expected";
+	cl_assert_equal_p(actual, actual); /* pointers to same object */
+	cl_assert_equal_p(&actual, actual);
+}
