t/README: document --root option

[git.git] / t / README

diff --git a/t/README b/t/README
index dcd3ebb5f2dcdbf15ca0e4a043b45cd2fc36cbb5..0e4e8d8862c96383a6f6f22a1b6bb01044925620 100644 (file)
--- a/t/README
+++ b/t/README
@@ -84,6 +84,12 @@ appropriately before running "make".
        implied by other options like --valgrind and
        GIT_TEST_INSTALLED.
 
+--root=<directory>::
+       Create "trash" directories used to store all temporary data during
+       testing under <directory>, instead of the t/ directory.
+       Using this option with a RAM-based filesystem (such as tmpfs)
+       can massively speed up the test suite.
+
 You can also set the GIT_TEST_INSTALLED environment variable to
 the bindir of an existing git installation to test that installation.
 You still need to have built this git sandbox, from which various