[PATCH] t/Makefile: add a rule to re-run previously-failed tests

While developing patch series, it is a good practice to run the test suite from time to time, just to make sure that obvious bugs are caught early. With complex patch series, it is common to run `make -j15 -k test`, i.e. run the tests in parallel and not stop at the first failing test but continue. This has the advantage of identifying possibly multiple problems without having to wait for the complete test suite to finish.

It is particularly important to reduce the turn-around time thusly on Windows, where the test suite spends 45 minutes on the computer on which this patch was developed.

It is the most convenient way to determine which tests failed after running the entire test suite, in parallel, to look for left-over "trash directory.t*" subdirectories in the t/ subdirectory.

This patch automates the process of determinig which tests failed previously and re-running them; It turned out to be quite convenient when trying to squash bugs that crept in during rebases.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
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Published-As: https://github.com/dscho/git/releases/tag/failing-tests-v1
 t/Makefile | 2 ++
 1 file changed, 2 insertions(+)