could be enabled by running the test suite with correct GIT_TEST_
environment set.
+GIT_TEST_GETTEXT_POISON=<non-empty?> turns all strings marked for
+translation into gibberish if non-empty (think "test -n"). Used for
+spotting those tests that need to be marked with a C_LOCALE_OUTPUT
+prerequisite when adding more strings for translation. See "Testing
+marked strings" in po/README for details.
+
GIT_TEST_SPLIT_INDEX=<boolean> forces split-index mode on the whole
test suite. Accept any boolean values that are accepted by git-config.
for the index version specified. Can be set to any valid version
(currently 2, 3, or 4).
+GIT_TEST_PACK_SPARSE=<boolean> if enabled will default the pack-objects
+builtin to use the sparse object walk. This can still be overridden by
+the --no-sparse command-line argument.
+
GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
by overriding the minimum number of cache entries required per thread.