"Test case body timed out" on 64-bit PowerPC

[awilfox]

I'm with Adélie Linux and we are trying to package Kyua for our distro (based on the musl libc). While running the Kyua self-test suite on our ppc64 builder (dual-CPU, 2.0 GHz), it had a single break:

===> Broken tests
utils/process/fdstream_test:ifdstream  ->  broken: Test case body timed out  [300.02s]
===> Summary
Results read from /home/awilcox/.kyua/store/results.usr_src_aports_main_kyua_src_kyua-0.13.20171125-220112-503300.db
Test cases: 1450 total, 21 skipped, 0 expected failures, 1 broken, 0 failed
Start time: 2017-11-25T22:01:12.659169Z
End time:   2017-11-25T22:08:50.251168Z
Total time: 434.000s

This computer isn't generally much slower than a Nehalem-era Xeon, so the fact it timed out surprised me. Perhaps there is something else amiss, such as a failure to read a result properly or a non-endian-safe lock resulting in a deadlock. I am not sure.