On 19 Jan 2017 3:47 p.m., "Ludovic Courtès" wrote: ... However, on my x86_64 machine, the build fails with: --8<---------------cut here---------------start------------->8--- 99% tests passed, 1 tests failed out of 751 Total Test time (real) = 2134.61 sec The following tests FAILED: 235 - std.datetime (Failed) Errors while running CTest make: *** [Makefile:76: test] Error 8 --8<---------------cut here---------------end--------------->8--- Any idea what’s amiss? If you have the time , look in builild/Testing/Temporary/Last test.log file in the debug folder created by guix with the --keep-failed flag: If you can't, I'll look at it when I get back to my computer. Thanks.