I'm seeing the "colors" tests fail with diffutils 3.8 and 3.9 as well, and the cause turns out to be a bit surprising.
The last test in "colors" checks that diff exits 141 (128 + SIGPIPE) when it's writing to a FIFO that is closed early. Modifying the test script to run diff under strace reveals that SIGPIPE's handler has been set to SIG_IGN when diff first queries it -- when it should be SIG_DFL by default. So diff's SIGPIPE handler doesn't run, and it exits 2 instead. It turns out this is a change in GNU Make 4.3.92 and later -- make does signal(SIGPIPE, SIG_IGN) for its own purposes, and its child processes inherit that. With make 4.3, the tests work; with 4.4, this one fails. I'm not sure whether this is a fault in make, diff or the test! There are other programs (e.g. the Python interpreter) that spawn processes with SIGPIPE set to SIG_IGN, so perhaps it should be robust against that. Cheers, -- Adam Sampson <a...@offog.org> <http://offog.org/>
