NixOS/hydra — comment on commit 597e7c04e1c283c8aae04b42143849f4f3240478
File: tests/Setup.pm line 53
By edolstra:

This looks wrong. The result of captureStdoutStderr is a list of 3 elements. In Perl, assigning a list to a scalar will store the length of the list in the scalar. So $res will always be 3, and failing commands will be ignored.