Investigating build failure on mips64el

Hi,

My recent upload of keyutils 1.5.9-7 initially FTBFS on mips64el, ppc64,
and alpha. All three shared the same cause: a specific test in the
post-build test suite execution failed.

Then, after failing to reproduce the issue in a QEMU instance, I was
surprised to see that in the meantime, an attempt to rebuild the package
on mips64el had completed successfully (after two failed attempts) [1].

Is there any way I can find out more about why the build failed on the
first two attempts? This might offer me clues as to why it also failed
on alpha and ppc64.

[1] https://buildd.debian.org/status/logs.php?pkg=keyutils&ver=1.5.9-7&arch=mips64el

Regards,
Christian

PS: It's really convenient that there are downloadable QEMU images for
mips64el!