thodg/libgit2

diff --git a/src/attr.c b/src/attr.c
index a7c65f9..603498d 100644
--- a/src/attr.c
+++ b/src/attr.c
@@ -408,10 +408,9 @@ void git_attr_cache_flush(
 		return;
 
 	if (repo->attrcache.files) {
-		const void *GIT_UNUSED(name);
 		git_attr_file *file;
 
-		GIT_HASHTABLE_FOREACH(repo->attrcache.files, name, file,
+		GIT_HASHTABLE_FOREACH_VALUE(repo->attrcache.files, file,
 			git_attr_file__free(file));
 
 		git_hashtable_free(repo->attrcache.files);
@@ -419,10 +418,9 @@ void git_attr_cache_flush(
 	}
 
 	if (repo->attrcache.macros) {
-		const void *GIT_UNUSED(name);
 		git_attr_rule *rule;
 
-		GIT_HASHTABLE_FOREACH(repo->attrcache.macros, name, rule,
+		GIT_HASHTABLE_FOREACH_VALUE(repo->attrcache.macros, rule,
 			git_attr_rule__free(rule));
 
 		git_hashtable_free(repo->attrcache.macros);
diff --git a/src/cc-compat.h b/src/cc-compat.h
index bbccd1f..3df36b6 100644
--- a/src/cc-compat.h
+++ b/src/cc-compat.h
@@ -33,8 +33,7 @@
 #	define GIT_TYPEOF(x)
 #endif
 
-#define GIT_UNUSED(x) x
-#define GIT_UNUSED_ARG(x) ((void)(x))
+#define GIT_UNUSED(x) ((void)(x))
 
 /* Define the printf format specifer to use for size_t output */
 #if defined(_MSC_VER) || defined(__MINGW32__)
diff --git a/src/config_file.c b/src/config_file.c
index ce76493..3c7c593 100644
--- a/src/config_file.c
+++ b/src/config_file.c
@@ -125,13 +125,12 @@ static int normalize_name(const char *in, char **out)
 
 static void free_vars(git_hashtable *values)
 {
-	const char *GIT_UNUSED(_unused) = NULL;
 	cvar_t *var = NULL;
 
 	if (values == NULL)
 		return;
 
-	GIT_HASHTABLE_FOREACH(values, _unused, var,
+	GIT_HASHTABLE_FOREACH_VALUE(values, var,
 	      do {
 		      cvar_t *next = CVAR_LIST_NEXT(var);
 		      cvar_free(var);
diff --git a/src/diff.c b/src/diff.c
index 9e41055..dcc0aef 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -325,7 +325,7 @@ static int maybe_modified(
 	int error = GIT_SUCCESS;
 	git_oid noid, *use_noid = NULL;
 
-	GIT_UNUSED_ARG(old);
+	GIT_UNUSED(old);
 
 	/* support "assume unchanged" & "skip worktree" bits */
 	if ((oitem->flags_extended & GIT_IDXENTRY_INTENT_TO_ADD) != 0 ||
diff --git a/src/diff_output.c b/src/diff_output.c
index ac60e98..b800be9 100644
--- a/src/diff_output.c
+++ b/src/diff_output.c
@@ -161,7 +161,7 @@ static int file_is_binary_by_content(
 	git_map *old_data,
 	git_map *new_data)
 {
-	GIT_UNUSED_ARG(diff);
+	GIT_UNUSED(diff);
 
 	if ((delta->old.flags & BINARY_DIFF_FLAGS) == 0) {
 		size_t search_len = min(old_data->len, 4000);
@@ -448,7 +448,7 @@ static int print_compact(void *data, git_diff_delta *delta, float progress)
 	diff_print_info *pi = data;
 	char code, old_suffix, new_suffix;
 
-	GIT_UNUSED_ARG(progress);
+	GIT_UNUSED(progress);
 
 	switch (delta->status) {
 	case GIT_STATUS_ADDED: code = 'A'; break;
@@ -546,7 +546,7 @@ static int print_patch_file(void *data, git_diff_delta *delta, float progress)
 	const char *newpfx = pi->diff->opts.dst_prefix;
 	const char *newpath = delta->new.path;
 
-	GIT_UNUSED_ARG(progress);
+	GIT_UNUSED(progress);
 
 	git_buf_clear(pi->buf);
 	git_buf_printf(pi->buf, "diff --git %s%s %s%s\n", oldpfx, delta->old.path, newpfx, delta->new.path);
@@ -593,8 +593,8 @@ static int print_patch_hunk(
 {
 	diff_print_info *pi = data;
 
-	GIT_UNUSED_ARG(d);
-	GIT_UNUSED_ARG(r);
+	GIT_UNUSED(d);
+	GIT_UNUSED(r);
 
 	git_buf_clear(pi->buf);
 
@@ -613,7 +613,7 @@ static int print_patch_line(
 {
 	diff_print_info *pi = data;
 
-	GIT_UNUSED_ARG(delta);
+	GIT_UNUSED(delta);
 
 	git_buf_clear(pi->buf);
 
diff --git a/src/hashtable.h b/src/hashtable.h
index f6fbb85..e099659 100644
--- a/src/hashtable.h
+++ b/src/hashtable.h
@@ -65,20 +65,20 @@ GIT_INLINE(int) git_hashtable_insert(git_hashtable *h, const void *key, void *va
 
 #define git_hashtable_node_at(nodes, pos) ((git_hashtable_node *)(&nodes[pos]))
 
-#define GIT_HASHTABLE_FOREACH(self, pkey, pvalue, code) {\
-	git_hashtable *_self = (self);\
-	git_hashtable_node *_nodes = _self->nodes;\
-	unsigned int _i, _size = _self->size;\
-	for (_i = 0; _i < _size; _i ++) {\
-		git_hashtable_node *_node = git_hashtable_node_at(_nodes, _i);\
-		if (_node->key)\
-		{\
-			pkey = _node->key;\
-			pvalue = _node->value;\
-			code;\
-		}\
-	}\
-}
+#define GIT_HASHTABLE__FOREACH(self,block) { \
+	unsigned int _c; \
+	git_hashtable_node *_n = (self)->nodes; \
+	for (_c = (self)->size; _c > 0; _c--, _n++)	{ \
+		if (!_n->key) continue; block } }
+
+#define GIT_HASHTABLE_FOREACH(self, pkey, pvalue, code)\
+	GIT_HASHTABLE__FOREACH(self,{(pkey)=_n->key;(pvalue)=_n->value;code;})
+
+#define GIT_HASHTABLE_FOREACH_KEY(self, pkey, code)\
+	GIT_HASHTABLE__FOREACH(self,{(pkey)=_n->key;code;})
+
+#define GIT_HASHTABLE_FOREACH_VALUE(self, pvalue, code)\
+	GIT_HASHTABLE__FOREACH(self,{(pvalue)=_n->value;code;})
 
 #define GIT_HASHTABLE_FOREACH_DELETE() {\
 	_node->key = NULL; _node->value = NULL; _self->key_count--;\
diff --git a/src/odb_pack.c b/src/odb_pack.c
index 9e1004e..249144a 100644
--- a/src/odb_pack.c
+++ b/src/odb_pack.c
@@ -159,9 +159,9 @@ static int pack_entry_find_prefix(struct git_pack_entry *e,
  *
  ***********************************************************/
 
-GIT_INLINE(void) pack_window_free_all(struct pack_backend *GIT_UNUSED(backend), struct git_pack_file *p)
+GIT_INLINE(void) pack_window_free_all(struct pack_backend *backend, struct git_pack_file *p)
 {
-	GIT_UNUSED_ARG(backend);
+	GIT_UNUSED(backend);
 	git_mwindow_free_all(&p->mwf);
 }
 
diff --git a/src/pkt.c b/src/pkt.c
index df972e7..51da55d 100644
--- a/src/pkt.c
+++ b/src/pkt.c
@@ -41,11 +41,11 @@ static int flush_pkt(git_pkt **out)
 }
 
 /* the rest of the line will be useful for multi_ack */
-static int ack_pkt(git_pkt **out, const char *GIT_UNUSED(line), size_t GIT_UNUSED(len))
+static int ack_pkt(git_pkt **out, const char *line, size_t len)
 {
 	git_pkt *pkt;
-	GIT_UNUSED_ARG(line);
-	GIT_UNUSED_ARG(len);
+	GIT_UNUSED(line);
+	GIT_UNUSED(len);
 
 	pkt = git__malloc(sizeof(git_pkt));
 	if (pkt == NULL)
diff --git a/src/refs.c b/src/refs.c
index 2e1d92d..f3388bf 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -105,7 +105,7 @@ static int reference_alloc(
 
 	reference->name = git__strdup(name);
 	if (reference->name == NULL) {
-		free(reference);
+		git__free(reference);
 		return GIT_ENOMEM;
 	}
 
@@ -222,7 +222,7 @@ static int loose_lookup(git_reference *ref)
 		return GIT_SUCCESS;
 
 	if (ref->flags & GIT_REF_SYMBOLIC) {
-		free(ref->target.symbolic);
+		git__free(ref->target.symbolic);
 		ref->target.symbolic = NULL;
 	}
 
@@ -278,7 +278,8 @@ static int loose_lookup_to_packfile(
 
 cleanup:
 	git_buf_free(&ref_file);
-	free(ref);
+	git__free(ref);
+
 	return git__rethrow(error, "Failed to lookup loose reference");
 }
 
@@ -420,7 +421,7 @@ static int packed_parse_oid(
 	return GIT_SUCCESS;
 
 cleanup:
-	free(ref);
+	git__free(ref);
 	return git__rethrow(error, "Failed to parse OID of packed reference");
 }
 
@@ -495,7 +496,7 @@ static int packed_load(git_repository *repo)
 
 		error = git_hashtable_insert(ref_cache->packfile, ref->name, ref);
 		if (error < GIT_SUCCESS) {
-			free(ref);
+			git__free(ref);
 			goto cleanup;
 		}
 	}
@@ -560,12 +561,12 @@ static int _dirent_loose_load(void *data, git_buf *full_path)
 		if (git_hashtable_insert2(
 			repository->references.packfile,
 			ref->name, ref, &old_ref) < GIT_SUCCESS) {
-			free(ref);
+			git__free(ref);
 			return GIT_ENOMEM;
 		}
 
 		if (old_ref != NULL)
-			free(old_ref);
+			git__free(old_ref);
 	}
 
 	return error == GIT_SUCCESS ?
@@ -773,9 +774,8 @@ static int packed_write(git_repository *repo)
 	/* Load all the packfile into a vector */
 	{
 		struct packref *reference;
-		const void *GIT_UNUSED(_unused);
 
-		GIT_HASHTABLE_FOREACH(repo->references.packfile, _unused, reference,
+		GIT_HASHTABLE_FOREACH_VALUE(repo->references.packfile, reference,
 			/* cannot fail: vector already has the right size */
 			git_vector_insert(&packing_list, reference);
 		);
@@ -929,7 +929,7 @@ static int packed_lookup(git_reference *ref)
 		return GIT_SUCCESS;
 
 	if (ref->flags & GIT_REF_SYMBOLIC) {
-		free(ref->target.symbolic);
+		git__free(ref->target.symbolic);
 		ref->target.symbolic = NULL;
 	}
 
@@ -1513,12 +1513,11 @@ int git_reference_foreach(
 	/* list all the packed references first */
 	if (list_flags & GIT_REF_PACKED) {
 		const char *ref_name;
-		void *GIT_UNUSED(_unused);
 
 		if ((error = packed_load(repo)) < GIT_SUCCESS)
 			return git__rethrow(error, "Failed to list references");
 
-		GIT_HASHTABLE_FOREACH(repo->references.packfile, ref_name, _unused,
+		GIT_HASHTABLE_FOREACH_KEY(repo->references.packfile, ref_name,
 			if ((error = callback(ref_name, payload)) < GIT_SUCCESS)
 				return git__throw(error,
 					"Failed to list references. User callback failed");
@@ -1595,12 +1594,10 @@ void git_repository__refcache_free(git_refcache *refs)
 	assert(refs);
 
 	if (refs->packfile) {
-		const void *GIT_UNUSED(_unused);
 		struct packref *reference;
 
-		GIT_HASHTABLE_FOREACH(refs->packfile, _unused, reference,
-			free(reference);
-		);
+		GIT_HASHTABLE_FOREACH_VALUE(
+			refs->packfile, reference, git__free(reference));
 
 		git_hashtable_free(refs->packfile);
 	}
diff --git a/src/remote.c b/src/remote.c
index 5b442e9..52b6aac 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -431,13 +431,13 @@ struct cb_data {
 	regex_t *preg;
 };
 
-static int remote_list_cb(const char *name, const char *GIT_UNUSED(value), void *data_)
+static int remote_list_cb(const char *name, const char *value, void *data_)
 {
 	struct cb_data *data = (struct cb_data *)data_;
 	size_t nmatch = 2;
 	regmatch_t pmatch[2];
 	int error;
-	GIT_UNUSED_ARG(value);
+	GIT_UNUSED(value);
 
 	if (!regexec(data->preg, name, nmatch, pmatch, 0)) {
 		char *remote_name = git__strndup(&name[pmatch[1].rm_so], pmatch[1].rm_eo - pmatch[1].rm_so);
diff --git a/src/revwalk.c b/src/revwalk.c
index cd971b5..997771f 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -590,7 +590,6 @@ int git_revwalk_new(git_revwalk **revwalk_out, git_repository *repo)
 void git_revwalk_free(git_revwalk *walk)
 {
 	unsigned int i;
-	const void *GIT_UNUSED(_unused);
 	commit_object *commit;
 
 	if (walk == NULL)
@@ -602,7 +601,7 @@ void git_revwalk_free(git_revwalk *walk)
 	/* if the parent has more than PARENTS_PER_COMMIT parents,
 	 * we had to allocate a separate array for those parents.
 	 * make sure it's being free'd */
-	GIT_HASHTABLE_FOREACH(walk->commits, _unused, commit, {
+	GIT_HASHTABLE_FOREACH_VALUE(walk->commits, commit, {
 		if (commit->out_degree > PARENTS_PER_COMMIT)
 			git__free(commit->parents);
 	});
@@ -669,12 +668,11 @@ int git_revwalk_next(git_oid *oid, git_revwalk *walk)
 
 void git_revwalk_reset(git_revwalk *walk)
 {
-	const void *GIT_UNUSED(_unused);
 	commit_object *commit;
 
 	assert(walk);
 
-	GIT_HASHTABLE_FOREACH(walk->commits, _unused, commit,
+	GIT_HASHTABLE_FOREACH_VALUE(walk->commits, commit,
 		commit->seen = 0;
 		commit->in_degree = 0;
 		commit->topo_delay = 0;
diff --git a/src/transport.c b/src/transport.c
index 672eb6e..785ddc3 100644
--- a/src/transport.c
+++ b/src/transport.c
@@ -43,9 +43,9 @@ static git_transport_cb transport_find_fn(const char *url)
  * Public API *
  **************/
 
-int git_transport_dummy(git_transport **GIT_UNUSED(transport))
+int git_transport_dummy(git_transport **transport)
 {
-	GIT_UNUSED_ARG(transport);
+	GIT_UNUSED(transport);
 	return git__throw(GIT_ENOTIMPLEMENTED, "This protocol isn't implemented. Sorry");
 }
 
diff --git a/src/transports/local.c b/src/transports/local.c
index 1dfc8ed..eb24db0 100644
--- a/src/transports/local.c
+++ b/src/transports/local.c
@@ -154,7 +154,7 @@ static int local_ls(git_transport *transport, git_headlist_cb list_cb, void *pay
  * Try to open the url as a git directory. The direction doesn't
  * matter in this case because we're calulating the heads ourselves.
  */
-static int local_connect(git_transport *transport, int GIT_UNUSED(direction))
+static int local_connect(git_transport *transport, int direction)
 {
 	git_repository *repo;
 	int error;
@@ -162,7 +162,7 @@ static int local_connect(git_transport *transport, int GIT_UNUSED(direction))
 	const char *path;
 	git_buf buf = GIT_BUF_INIT;
 
-	GIT_UNUSED_ARG(direction);
+	GIT_UNUSED(direction);
 
 	/* The repo layer doesn't want the prefix */
 	if (!git__prefixcmp(transport->url, "file://")) {
@@ -194,7 +194,7 @@ static int local_connect(git_transport *transport, int GIT_UNUSED(direction))
 	return GIT_SUCCESS;
 }
 
-static int local_close(git_transport *GIT_UNUSED(transport))
+static int local_close(git_transport *transport)
 {
 	transport_local *t = (transport_local *)transport;
 
diff --git a/src/win32/posix.h b/src/win32/posix.h
index f4c1c12..60adc96 100644
--- a/src/win32/posix.h
+++ b/src/win32/posix.h
@@ -11,20 +11,20 @@
 #include "fnmatch.h"
 #include "utf-conv.h"
 
-GIT_INLINE(int) p_link(const char *GIT_UNUSED(old), const char *GIT_UNUSED(new))
+GIT_INLINE(int) p_link(const char *old, const char *new)
 {
-	GIT_UNUSED_ARG(old);
-	GIT_UNUSED_ARG(new);
+	GIT_UNUSED(old);
+	GIT_UNUSED(new);
 	errno = ENOSYS;
 	return -1;
 }
 
-GIT_INLINE(int) p_mkdir(const char *path, mode_t GIT_UNUSED(mode))
+GIT_INLINE(int) p_mkdir(const char *path, mode_t mode)
 {
 	wchar_t* buf = gitwin_to_utf16(path);
 	int ret = _wmkdir(buf);
 
-	GIT_UNUSED_ARG(mode);
+	GIT_UNUSED(mode);
 
 	git__free(buf);
 	return ret;
diff --git a/src/win32/pthread.c b/src/win32/pthread.c
index cbce639..3db5368 100644
--- a/src/win32/pthread.c
+++ b/src/win32/pthread.c
@@ -8,10 +8,10 @@
 #include "pthread.h"
 
 int pthread_create(pthread_t *GIT_RESTRICT thread,
-					const pthread_attr_t *GIT_RESTRICT GIT_UNUSED(attr),
+					const pthread_attr_t *GIT_RESTRICT attr,
 					void *(*start_routine)(void*), void *GIT_RESTRICT arg)
 {
-	GIT_UNUSED_ARG(attr);
+	GIT_UNUSED(attr);
 	*thread = (pthread_t) CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)start_routine, arg, 0, NULL);
 	return *thread ? GIT_SUCCESS : git__throw(GIT_EOSERR, "Failed to create pthread");
 }
@@ -26,9 +26,9 @@ int pthread_join(pthread_t thread, void **value_ptr)
 }
 
 int pthread_mutex_init(pthread_mutex_t *GIT_RESTRICT mutex,
-						const pthread_mutexattr_t *GIT_RESTRICT GIT_UNUSED(mutexattr))
+						const pthread_mutexattr_t *GIT_RESTRICT mutexattr)
 {
-	GIT_UNUSED_ARG(mutexattr);
+	GIT_UNUSED(mutexattr);
 	InitializeCriticalSection(mutex);
 	return 0;
 }
diff --git a/tests-clar/attr/repo.c b/tests-clar/attr/repo.c
index 9f6a49b..2afea23 100644
--- a/tests-clar/attr/repo.c
+++ b/tests-clar/attr/repo.c
@@ -104,12 +104,12 @@ void test_attr_repo__get_many(void)
 }
 
 static int count_attrs(
-	const char *GIT_UNUSED(name),
-	const char *GIT_UNUSED(value),
+	const char *name,
+	const char *value,
 	void *payload)
 {
-	GIT_UNUSED_ARG(name);
-	GIT_UNUSED_ARG(value);
+	GIT_UNUSED(name);
+	GIT_UNUSED(value);
 
 	*((int *)payload) += 1;
 
diff --git a/tests-clar/clar_helpers.c b/tests-clar/clar_helpers.c
index 1ef5a9b..22db56f 100644
--- a/tests-clar/clar_helpers.c
+++ b/tests-clar/clar_helpers.c
@@ -39,3 +39,52 @@ void cl_git_append2file(const char *filename, const char *new_content)
 	cl_must_pass(p_chmod(filename, 0644));
 }
 
+static const char *_cl_sandbox = NULL;
+static git_repository *_cl_repo = NULL;
+
+git_repository *cl_git_sandbox_init(const char *sandbox)
+{
+	/* Copy the whole sandbox folder from our fixtures to our test sandbox
+	 * area.  After this it can be accessed with `./sandbox`
+	 */
+	cl_fixture_sandbox(sandbox);
+	_cl_sandbox = sandbox;
+
+	p_chdir(sandbox);
+
+	/* Rename `sandbox/.gitted` to `sandbox/.git` which must be done since
+	 * we cannot store a folder named `.git` inside the fixtures folder of
+	 * our libgit2 repo.
+	 */
+	cl_git_pass(p_rename(".gitted", ".git"));
+
+	/* If we have `gitattributes`, rename to `.gitattributes`.  This may
+	 * be necessary if we don't want the attributes to be applied in the
+	 * libgit2 repo, but just during testing.
+	 */
+	if (p_access("gitattributes", F_OK) == 0)
+		cl_git_pass(p_rename("gitattributes", ".gitattributes"));
+
+	/* As with `gitattributes`, we may need `gitignore` just for testing. */
+	if (p_access("gitignore", F_OK) == 0)
+		cl_git_pass(p_rename("gitignore", ".gitignore"));
+
+	p_chdir("..");
+
+	/* Now open the sandbox repository and make it available for tests */
+	cl_git_pass(git_repository_open(&_cl_repo, sandbox));
+
+	return _cl_repo;
+}
+
+void cl_git_sandbox_cleanup(void)
+{
+	if (_cl_repo) {
+		git_repository_free(_cl_repo);
+		_cl_repo = NULL;
+	}
+	if (_cl_sandbox) {
+		cl_fixture_cleanup(_cl_sandbox);
+		_cl_sandbox = NULL;
+	}
+}
diff --git a/tests-clar/clar_libgit2.h b/tests-clar/clar_libgit2.h
index 43dc4e8..5c034a3 100644
--- a/tests-clar/clar_libgit2.h
+++ b/tests-clar/clar_libgit2.h
@@ -58,4 +58,9 @@ GIT_INLINE(void) cl_assert_strequal_internal(
 void cl_git_mkfile(const char *filename, const char *content);
 void cl_git_append2file(const char *filename, const char *new_content);
 
+/* Git sandbox setup helpers */
+
+git_repository *cl_git_sandbox_init(const char *sandbox);
+void cl_git_sandbox_cleanup(void);
+
 #endif
diff --git a/tests-clar/config/multivar.c b/tests-clar/config/multivar.c
index bccdc12..a8451ac 100644
--- a/tests-clar/config/multivar.c
+++ b/tests-clar/config/multivar.c
@@ -12,10 +12,12 @@ void test_config_multivar__cleanup(void)
 	cl_fixture_cleanup("config");
 }
 
-static int mv_read_cb(const char *name, const char *GIT_UNUSED(value), void *data)
+static int mv_read_cb(const char *name, const char *value, void *data)
 {
 	int *n = (int *) data;
 
+	GIT_UNUSED(value);
+
 	if (!strcmp(name, _name))
 		(*n)++;
 
@@ -35,10 +37,12 @@ void test_config_multivar__foreach(void)
 	git_config_free(cfg);
 }
 
-static int cb(const char *GIT_UNUSED(val), void *data)
+static int cb(const char *val, void *data)
 {
 	int *n = (int *) data;
 
+	GIT_UNUSED(val);
+
 	(*n)++;
 
 	return GIT_SUCCESS;
diff --git a/tests-clar/core/dirent.c b/tests-clar/core/dirent.c
index 7823709..9c366bf 100644
--- a/tests-clar/core/dirent.c
+++ b/tests-clar/core/dirent.c
@@ -88,10 +88,10 @@ static int one_entry(void *state, git_buf *path)
 	return GIT_ERROR;
 }
 
-static int dont_call_me(void *GIT_UNUSED(state), git_buf *GIT_UNUSED(path))
+static int dont_call_me(void *state, git_buf *path)
 {
-	GIT_UNUSED_ARG(state);
-	GIT_UNUSED_ARG(path);
+	GIT_UNUSED(state);
+	GIT_UNUSED(path);
 	return GIT_ERROR;
 }
 
diff --git a/tests-clar/diff/blob.c b/tests-clar/diff/blob.c
index 7aa8ceb..bdfe8ba 100644
--- a/tests-clar/diff/blob.c
+++ b/tests-clar/diff/blob.c
@@ -5,17 +5,12 @@ static git_repository *g_repo = NULL;
 
 void test_diff_blob__initialize(void)
 {
-	cl_fixture_sandbox("attr");
-	cl_git_pass(p_rename("attr/.gitted", "attr/.git"));
-	cl_git_pass(p_rename("attr/gitattributes", "attr/.gitattributes"));
-	cl_git_pass(git_repository_open(&g_repo, "attr/.git"));
+	g_repo = cl_git_sandbox_init("attr");
 }
 
 void test_diff_blob__cleanup(void)
 {
-	git_repository_free(g_repo);
-	g_repo = NULL;
-	cl_fixture_cleanup("attr");
+	cl_git_sandbox_cleanup();
 }
 
 void test_diff_blob__0(void)
diff --git a/tests-clar/diff/index.c b/tests-clar/diff/index.c
index 0941c7c..171815d 100644
--- a/tests-clar/diff/index.c
+++ b/tests-clar/diff/index.c
@@ -5,16 +5,12 @@ static git_repository *g_repo = NULL;
 
 void test_diff_index__initialize(void)
 {
-	cl_fixture_sandbox("status");
-	cl_git_pass(p_rename("status/.gitted", "status/.git"));
-	cl_git_pass(git_repository_open(&g_repo, "status/.git"));
+	g_repo = cl_git_sandbox_init("status");
 }
 
 void test_diff_index__cleanup(void)
 {
-	git_repository_free(g_repo);
-	g_repo = NULL;
-	cl_fixture_cleanup("status");
+	cl_git_sandbox_cleanup();
 }
 
 void test_diff_index__0(void)
diff --git a/tests-clar/diff/iterator.c b/tests-clar/diff/iterator.c
index 1ad126c..3953fd8 100644
--- a/tests-clar/diff/iterator.c
+++ b/tests-clar/diff/iterator.c
@@ -2,37 +2,6 @@
 #include "diff_helpers.h"
 #include "iterator.h"
 
-static git_repository *g_repo = NULL;
-static const char *g_sandbox = NULL;
-
-static void setup_sandbox(const char *sandbox)
-{
-	cl_fixture_sandbox(sandbox);
-	g_sandbox = sandbox;
-
-	p_chdir(sandbox);
-	cl_git_pass(p_rename(".gitted", ".git"));
-	if (p_access("gitattributes", F_OK) == 0)
-		cl_git_pass(p_rename("gitattributes", ".gitattributes"));
-	if (p_access("gitignore", F_OK) == 0)
-		cl_git_pass(p_rename("gitignore", ".gitignore"));
-	p_chdir("..");
-
-	cl_git_pass(git_repository_open(&g_repo, sandbox));
-}
-
-static void cleanup_sandbox(void)
-{
-	if (g_repo) {
-		git_repository_free(g_repo);
-		g_repo = NULL;
-	}
-	if (g_sandbox) {
-		cl_fixture_cleanup(g_sandbox);
-		g_sandbox = NULL;
-	}
-}
-
 void test_diff_iterator__initialize(void)
 {
 	/* since we are doing tests with different sandboxes, defer setup
@@ -44,7 +13,7 @@ void test_diff_iterator__initialize(void)
 
 void test_diff_iterator__cleanup(void)
 {
-	cleanup_sandbox();
+	cl_git_sandbox_cleanup();
 }
 
 
@@ -60,11 +29,10 @@ static void tree_iterator_test(
 	git_iterator *i;
 	const git_index_entry *entry;
 	int count = 0;
+	git_repository *repo = cl_git_sandbox_init(sandbox);
 
-	setup_sandbox(sandbox);
-
-	cl_assert(t = resolve_commit_oid_to_tree(g_repo, treeish));
-	cl_git_pass(git_iterator_for_tree(g_repo, t, &i));
+	cl_assert(t = resolve_commit_oid_to_tree(repo, treeish));
+	cl_git_pass(git_iterator_for_tree(repo, t, &i));
 	cl_git_pass(git_iterator_current(i, &entry));
 
 	while (entry != NULL) {
@@ -183,10 +151,9 @@ static void index_iterator_test(
 	git_iterator *i;
 	const git_index_entry *entry;
 	int count = 0;
+	git_repository *repo = cl_git_sandbox_init(sandbox);
 
-	setup_sandbox(sandbox);
-
-	cl_git_pass(git_iterator_for_index(g_repo, &i));
+	cl_git_pass(git_iterator_for_index(repo, &i));
 	cl_git_pass(git_iterator_current(i, &entry));
 
 	while (entry != NULL) {
@@ -303,10 +270,9 @@ static void workdir_iterator_test(
 	git_iterator *i;
 	const git_index_entry *entry;
 	int count = 0, count_all = 0;
+	git_repository *repo = cl_git_sandbox_init(sandbox);
 
-	setup_sandbox(sandbox);
-
-	cl_git_pass(git_iterator_for_workdir(g_repo, &i));
+	cl_git_pass(git_iterator_for_workdir(repo, &i));
 	cl_git_pass(git_iterator_current(i, &entry));
 
 	while (entry != NULL) {
diff --git a/tests-clar/diff/tree.c b/tests-clar/diff/tree.c
index f5fdfba..91e1343 100644
--- a/tests-clar/diff/tree.c
+++ b/tests-clar/diff/tree.c
@@ -5,17 +5,12 @@ static git_repository *g_repo = NULL;
 
 void test_diff_tree__initialize(void)
 {
-	cl_fixture_sandbox("attr");
-	cl_git_pass(p_rename("attr/.gitted", "attr/.git"));
-	cl_git_pass(p_rename("attr/gitattributes", "attr/.gitattributes"));
-	cl_git_pass(git_repository_open(&g_repo, "attr/.git"));
+	g_repo = cl_git_sandbox_init("attr");
 }
 
 void test_diff_tree__cleanup(void)
 {
-	git_repository_free(g_repo);
-	g_repo = NULL;
-	cl_fixture_cleanup("attr");
+	cl_git_sandbox_cleanup();
 }
 
 void test_diff_tree__0(void)
diff --git a/tests-clar/diff/workdir.c b/tests-clar/diff/workdir.c
index 7312a72..28cfa23 100644
--- a/tests-clar/diff/workdir.c
+++ b/tests-clar/diff/workdir.c
@@ -5,16 +5,12 @@ static git_repository *g_repo = NULL;
 
 void test_diff_workdir__initialize(void)
 {
-	cl_fixture_sandbox("status");
-	cl_git_pass(p_rename("status/.gitted", "status/.git"));
-	cl_git_pass(git_repository_open(&g_repo, "status/.git"));
+	g_repo = cl_git_sandbox_init("status");
 }
 
 void test_diff_workdir__cleanup(void)
 {
-	git_repository_free(g_repo);
-	g_repo = NULL;
-	cl_fixture_cleanup("status");
+	cl_git_sandbox_cleanup();
 }
 
 void test_diff_workdir__to_index(void)
diff --git a/tests-clar/status/ignore.c b/tests-clar/status/ignore.c
index 67aecba..99cb9e8 100644
--- a/tests-clar/status/ignore.c
+++ b/tests-clar/status/ignore.c
@@ -7,21 +7,12 @@ static git_repository *g_repo = NULL;
 
 void test_status_ignore__initialize(void)
 {
-	/* Before each test, instantiate the attr repo from the fixtures and
-	 * rename the .gitted to .git so it is a repo with a working dir.  Also
-	 * rename gitignore to .gitignore.
-	 */
-	cl_fixture_sandbox("attr");
-	cl_git_pass(p_rename("attr/.gitted", "attr/.git"));
-	cl_git_pass(p_rename("attr/gitignore", "attr/.gitignore"));
-	cl_git_pass(git_repository_open(&g_repo, "attr/.git"));
+	g_repo = cl_git_sandbox_init("attr");
 }
 
 void test_status_ignore__cleanup(void)
 {
-	git_repository_free(g_repo);
-	g_repo = NULL;
-	cl_fixture_cleanup("attr");
+	cl_git_sandbox_cleanup();
 }
 
 void test_status_ignore__0(void)
diff --git a/tests-clar/status/worktree.c b/tests-clar/status/worktree.c
index 7d730bb..f654b8a 100644
--- a/tests-clar/status/worktree.c
+++ b/tests-clar/status/worktree.c
@@ -5,12 +5,6 @@
 
 
 /**
- * Test fixtures
- */
-static git_repository *_repository = NULL;
-
-
-/**
  * Auxiliary methods
  */
 static int
@@ -37,48 +31,27 @@ exit:
 }
 
 static int
-cb_status__count(const char *GIT_UNUSED(p), unsigned int GIT_UNUSED(s), void *payload)
+cb_status__count(const char *p, unsigned int s, void *payload)
 {
 	volatile int *count = (int *)payload;
 
-	GIT_UNUSED_ARG(p);
-	GIT_UNUSED_ARG(s);
+	GIT_UNUSED(p);
+	GIT_UNUSED(s);
 
-	*count++;
+	(*count)++;
 
 	return GIT_SUCCESS;
 }
 
 
-
 /**
  * Initializer
  *
- * This method is called once before starting each
- * test, and will load the required fixtures
+ * Not all of the tests in this file use the same fixtures, so we allow each
+ * test to load their fixture at the top of the test function.
  */
 void test_status_worktree__initialize(void)
 {
-	/*
-	 * Sandbox the `status/` repository from our Fixtures.
-	 * This will copy the whole folder to our sandbox,
-	 * so now it can be accessed with `./status`
-	 */
-	cl_fixture_sandbox("status");
-
-	/*
-	 * Rename `status/.gitted` to `status/.git`
-	 * We do this because we cannot store a folder named `.git`
-	 * inside the fixtures folder in our libgit2 repo.
-	 */
-	cl_git_pass(
-		p_rename("status/.gitted", "status/.git")
-	);
-
-	/*
-	 * Open the sandboxed "status" repository
-	 */
-	cl_git_pass(git_repository_open(&_repository, "status/.git"));
 }
 
 /**
@@ -89,10 +62,7 @@ void test_status_worktree__initialize(void)
  */
 void test_status_worktree__cleanup(void)
 {
-	git_repository_free(_repository);
-	_repository = NULL;
-
-	cl_fixture_cleanup("status");
+	cl_git_sandbox_cleanup();
 }
 
 /**
@@ -101,6 +71,7 @@ void test_status_worktree__cleanup(void)
 void test_status_worktree__whole_repository(void)
 {
 	struct status_entry_counts counts;
+	git_repository *repo = cl_git_sandbox_init("status");
 
 	memset(&counts, 0x0, sizeof(struct status_entry_counts));
 	counts.expected_entry_count = entry_count0;
@@ -108,7 +79,7 @@ void test_status_worktree__whole_repository(void)
 	counts.expected_statuses = entry_statuses0;
 
 	cl_git_pass(
-		git_status_foreach(_repository, cb_status__normal, &counts)
+		git_status_foreach(repo, cb_status__normal, &counts)
 	);
 
 	cl_assert(counts.entry_count == counts.expected_entry_count);
@@ -119,8 +90,10 @@ void test_status_worktree__whole_repository(void)
 void test_status_worktree__empty_repository(void)
 {
 	int count = 0;
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo");
+
+	cl_git_pass(git_status_foreach(repo, cb_status__count, &count));
 
-	git_status_foreach(_repository, cb_status__count, &count);
 	cl_assert(count == 0);
 }
 
@@ -128,10 +101,11 @@ void test_status_worktree__single_file(void)
 {
 	int i;
 	unsigned int status_flags;
+	git_repository *repo = cl_git_sandbox_init("status");
 
 	for (i = 0; i < (int)entry_count0; i++) {
 		cl_git_pass(
-			git_status_file(&status_flags, _repository, entry_paths0[i])
+			git_status_file(&status_flags, repo, entry_paths0[i])
 		);
 		cl_assert(entry_statuses0[i] == status_flags);
 	}
@@ -140,15 +114,22 @@ void test_status_worktree__single_file(void)
 void test_status_worktree__ignores(void)
 {
 	int i, ignored;
+	git_repository *repo = cl_git_sandbox_init("status");
 
 	for (i = 0; i < (int)entry_count0; i++) {
-		cl_git_pass(git_status_should_ignore(_repository, entry_paths0[i], &ignored));
+		cl_git_pass(
+			git_status_should_ignore(repo, entry_paths0[i], &ignored)
+		);
 		cl_assert(ignored == (entry_statuses0[i] == GIT_STATUS_WT_IGNORED));
 	}
 
-	cl_git_pass(git_status_should_ignore(_repository, "nonexistent_file", &ignored));
+	cl_git_pass(
+		git_status_should_ignore(repo, "nonexistent_file", &ignored)
+	);
 	cl_assert(!ignored);
 
-	cl_git_pass(git_status_should_ignore(_repository, "ignored_nonexistent_file", &ignored));
+	cl_git_pass(
+		git_status_should_ignore(repo, "ignored_nonexistent_file", &ignored)
+	);
 	cl_assert(ignored);
 }
diff --git a/tests/t00-core.c b/tests/t00-core.c
index aff48b0..7f142ba 100644
--- a/tests/t00-core.c
+++ b/tests/t00-core.c
@@ -424,10 +424,10 @@ static walk_data empty = {
 	GIT_BUF_INIT
 };
 
-static int dont_call_me(void *GIT_UNUSED(state), git_buf *GIT_UNUSED(path))
+static int dont_call_me(void *state, git_buf *path)
 {
-	GIT_UNUSED_ARG(state);
-	GIT_UNUSED_ARG(path);
+	GIT_UNUSED(state);
+	GIT_UNUSED(path);
 	return GIT_ERROR;
 }
 
diff --git a/tests/t07-hashtable.c b/tests/t07-hashtable.c
index 41d52af..6beaeac 100644
--- a/tests/t07-hashtable.c
+++ b/tests/t07-hashtable.c
@@ -154,7 +154,6 @@ BEGIN_TEST(tableit0, "iterate through all the contents of the table")
 	const int objects_n = 32;
 	int i;
 	table_item *objects, *ob;
-	const void *GIT_UNUSED(_unused);
 
 	git_hashtable *table = NULL;
 
@@ -170,9 +169,7 @@ BEGIN_TEST(tableit0, "iterate through all the contents of the table")
 		must_pass(git_hashtable_insert(table, &(objects[i].id), &(objects[i])));
 	}
 
-	GIT_HASHTABLE_FOREACH(table, _unused, ob,
-		ob->visited = 1;
-	);
+	GIT_HASHTABLE_FOREACH_VALUE(table, ob, ob->visited = 1);
 
 	/* make sure all nodes have been visited */
 	for (i = 0; i < objects_n; ++i)
diff --git a/tests/t18-status.c b/tests/t18-status.c
index 8bccb71..aeadd5e 100644
--- a/tests/t18-status.c
+++ b/tests/t18-status.c
@@ -156,14 +156,14 @@ BEGIN_TEST(statuscb0, "test retrieving status for worktree of repository")
 	git_futils_rmdir_r(TEMP_REPO_FOLDER, 1);
 END_TEST
 
-static int status_cb1(const char *GIT_UNUSED(path), unsigned int GIT_UNUSED(status_flags), void *payload)
+static int status_cb1(const char *path, unsigned int status_flags, void *payload)
 {
 	int *count = (int *)payload;;
 
-	GIT_UNUSED_ARG(path);
-	GIT_UNUSED_ARG(status_flags);
+	GIT_UNUSED(path);
+	GIT_UNUSED(status_flags);
 
-	(void) *count++;
+	(*count)++;
 
 	return GIT_SUCCESS;
 }
diff --git a/tests/test_main.c b/tests/test_main.c
index 732d25a..50256e9 100644
--- a/tests/test_main.c
+++ b/tests/test_main.c
@@ -70,12 +70,12 @@ int __cdecl
 #else
 int
 #endif
-main(int GIT_UNUSED(argc), char *GIT_UNUSED(argv[]))
+main(int argc, char *argv[])
 {
 	unsigned int i, failures;
 
-	GIT_UNUSED_ARG(argc);
-	GIT_UNUSED_ARG(argv);
+	GIT_UNUSED(argc);
+	GIT_UNUSED(argv);
 
 	git_threads_init();