diff --git a/Makefile b/Makefile
index 5bf1af369e..d18ab0fe78 100644
--- a/Makefile
+++ b/Makefile
@@ -400,7 +400,7 @@ all::
 # (defaults to "man") if you want to have a different default when
 # "git help" is called without a parameter specifying the format.
 #
-# Define TEST_GIT_INDEX_VERSION to 2, 3 or 4 to run the test suite
+# Define GIT_TEST_INDEX_VERSION to 2, 3 or 4 to run the test suite
 # with a different indexfile format version.  If it isn't set the index
 # file format used is index-v[23].
 #
@@ -2610,8 +2610,8 @@ endif
 ifdef GIT_INTEROP_MAKE_OPTS
 	@echo GIT_INTEROP_MAKE_OPTS=\''$(subst ','\'',$(subst ','\'',$(GIT_INTEROP_MAKE_OPTS)))'\' >>$@+
 endif
-ifdef TEST_GIT_INDEX_VERSION
-	@echo TEST_GIT_INDEX_VERSION=\''$(subst ','\'',$(subst ','\'',$(TEST_GIT_INDEX_VERSION)))'\' >>$@+
+ifdef GIT_TEST_INDEX_VERSION
+	@echo GIT_TEST_INDEX_VERSION=\''$(subst ','\'',$(subst ','\'',$(GIT_TEST_INDEX_VERSION)))'\' >>$@+
 endif
 	@if cmp $@+ $@ >/dev/null 2>&1; then $(RM) $@+; else mv $@+ $@; fi
 
diff --git a/config.c b/config.c
index 3461993f0a..3555c63f28 100644
--- a/config.c
+++ b/config.c
@@ -2278,7 +2278,7 @@ int git_config_get_max_percent_split_change(void)
 int git_config_get_fsmonitor(void)
 {
 	if (git_config_get_pathname("core.fsmonitor", &core_fsmonitor))
-		core_fsmonitor = getenv("GIT_FSMONITOR_TEST");
+		core_fsmonitor = getenv("GIT_TEST_FSMONITOR");
 
 	if (core_fsmonitor && !*core_fsmonitor)
 		core_fsmonitor = NULL;
diff --git a/preload-index.c b/preload-index.c
index f7365761f4..16dc5ad868 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -5,6 +5,7 @@
 #include "pathspec.h"
 #include "dir.h"
 #include "fsmonitor.h"
+#include "config.h"
 
 #ifdef NO_PTHREADS
 static void preload_index(struct index_state *index,
@@ -83,7 +84,7 @@ static void preload_index(struct index_state *index,
 		return;
 
 	threads = index->cache_nr / THREAD_COST;
-	if ((index->cache_nr > 1) && (threads < 2) && getenv("GIT_FORCE_PRELOAD_TEST"))
+	if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_TEST_PRELOAD_INDEX", 0))
 		threads = 2;
 	if (threads < 2)
 		return;
diff --git a/t/README b/t/README
index 4d8dbc7c5f..d8b04c35c0 100644
--- a/t/README
+++ b/t/README
@@ -315,7 +315,7 @@ packs on demand. This normally only happens when the object size is
 over 2GB. This variable forces the code path on any object larger than
 <n> bytes.
 
-GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncomon pack-objects code
+GIT_TEST_OE_DELTA_SIZE=<n> exercises the uncommon pack-objects code
 path where deltas larger than this limit require extra memory
 allocation for bookkeeping.
 
@@ -327,6 +327,17 @@ GIT_TEST_COMMIT_GRAPH=<boolean>, when true, forces the commit-graph to
 be written after every 'git commit' command, and overrides the
 'core.commitGraph' setting to true.
 
+GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor
+code path for utilizing a file system monitor to speed up detecting
+new or changed files.
+
+GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path
+for the index version specified.  Can be set to any valid version
+(currently 2, 3, or 4).
+
+GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
+by overriding the minimum number of cache entries required per thread.
+
 Naming Tests
 ------------
 
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 26601e698b..4d23373526 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -87,6 +87,10 @@ _run_sub_test_lib_test_common () {
 		passing metrics
 		'
 
+		# Tell the framework that we are self-testing to make sure
+		# it yields a stable result.
+		GIT_TEST_FRAMEWORK_SELFTEST=t &&
+
 		# Point to the t/test-lib.sh, which isn't in ../ as usual
 		. "\$TEST_DIRECTORY"/test-lib.sh
 		EOF
diff --git a/t/t1700-split-index.sh b/t/t1700-split-index.sh
index be22398a85..8f8807d1c1 100755
--- a/t/t1700-split-index.sh
+++ b/t/t1700-split-index.sh
@@ -6,7 +6,7 @@ test_description='split index mode tests'
 
 # We need total control of index splitting here
 sane_unset GIT_TEST_SPLIT_INDEX
-sane_unset GIT_FSMONITOR_TEST
+sane_unset GIT_TEST_FSMONITOR
 
 test_expect_success 'enable split index' '
 	git config splitIndex.maxPercentChange 100 &&
diff --git a/t/t7519-status-fsmonitor.sh b/t/t7519-status-fsmonitor.sh
index 8384ad258c..3e0a61db23 100755
--- a/t/t7519-status-fsmonitor.sh
+++ b/t/t7519-status-fsmonitor.sh
@@ -4,13 +4,6 @@ test_description='git status with file system watcher'
 
 . ./test-lib.sh
 
-#
-# To run the entire git test suite using fsmonitor:
-#
-# copy t/t7519/fsmonitor-all to a location in your path and then set
-# GIT_FSMONITOR_TEST=fsmonitor-all and run your tests.
-#
-
 # Note, after "git reset --hard HEAD" no extensions exist other than 'TREE'
 # "git update-index --fsmonitor" can be used to get the extension written
 # before testing the results.
@@ -245,9 +238,9 @@ do
 		git config core.preloadIndex $preload_val &&
 		if test $preload_val = true
 		then
-			GIT_FORCE_PRELOAD_TEST=$preload_val; export GIT_FORCE_PRELOAD_TEST
+			GIT_TEST_PRELOAD_INDEX=$preload_val; export GIT_TEST_PRELOAD_INDEX
 		else
-			unset GIT_FORCE_PRELOAD_TEST
+			sane_unset GIT_TEST_PRELOAD_INDEX
 		fi
 	'
 
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 3f95bfda60..897e6fcc94 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -134,9 +134,40 @@ export EDITOR
 GIT_TRACE_BARE=1
 export GIT_TRACE_BARE
 
-if test -n "${TEST_GIT_INDEX_VERSION:+isset}"
+check_var_migration () {
+	# the warnings and hints given from this helper depends
+	# on end-user settings, which will disrupt the self-test
+	# done on the test framework itself.
+	case "$GIT_TEST_FRAMEWORK_SELFTEST" in
+	t)	return ;;
+	esac
+
+	old_name=$1 new_name=$2
+	eval "old_isset=\${${old_name}:+isset}"
+	eval "new_isset=\${${new_name}:+isset}"
+
+	case "$old_isset,$new_isset" in
+	isset,)
+		echo >&2 "warning: $old_name is now $new_name"
+		echo >&2 "hint: set $new_name too during the transition period"
+		eval "$new_name=\$$old_name"
+		;;
+	isset,isset)
+		# do this later
+		# echo >&2 "warning: $old_name is now $new_name"
+		# echo >&2 "hint: remove $old_name"
+		;;
+	esac
+}
+
+check_var_migration GIT_FSMONITOR_TEST GIT_TEST_FSMONITOR
+check_var_migration TEST_GIT_INDEX_VERSION GIT_TEST_INDEX_VERSION
+check_var_migration GIT_FORCE_PRELOAD_TEST GIT_TEST_PRELOAD_INDEX
+
+# Use specific version of the index file format
+if test -n "${GIT_TEST_INDEX_VERSION:+isset}"
 then
-	GIT_INDEX_VERSION="$TEST_GIT_INDEX_VERSION"
+	GIT_INDEX_VERSION="$GIT_TEST_INDEX_VERSION"
 	export GIT_INDEX_VERSION
 fi