Hello GHC developers, the testsuite driver now runs each test in a temporary directory in /tmp, after first linking/copying all files that the test requires to that directory. When adding a new test: ** if your test requires source files that don't start with the name of your test, then you *have to* specify those files using the `extra_files` setup function. [1]* * you no longer have to specify files to cleanup (`clean_files` and `clean_cmd` are deprecated) * you no longer have to add generated files to `testsuite/.gitignore` * you no longer have to worry about two tests possibly overwriting each others intermediate (.o, .hi) files, and you no longer have to specify `-outputdir` if you want to let multiple tests use the same source files. Example: *BEFORE:* test('driver011', extra_clean(['A011.hi', 'A011.o']), run_command, ['$MAKE -s --no-print-directory test011']) *AFTER:* test('driver011', extra_files(['A011.hs']), run_command, ['$MAKE -s --no-print-directory test011']) See https://ghc.haskell.org/trac/ghc/ticket/11980 and https://ghc.haskell.org/trac/ghc/wiki/Building/RunningTests/Adding for more information. Cheers, Thomas [1] Extra files for existing tests are currently listed in `testsuite/driver/extra_files.py`.