Not particularly related to the issue at hand (which is probably polkitqt having meh cmake files), but relocating stuff in general is suuuuper unreliable and I would absolutely advise against it as it can easily screw up test results and builds alike, often in unobvious ways (all it takes is a bit of libexec use). Instead, as a general principle, I would suggest that you get stuff mounted in suitably stable/consistent/generic paths inside the build containers. Ultimately what things look like natively on the host file system shouldn't factor into what they look like in the build environment.
For example, in neon we simply mount everything into /workspace of our containers. You could have /workspace |_ src/ [on host: /home/jenkins/workspace/polkit-qt-1 kf5-qt5 XenialQt5.7/ |_ install/ [on host: /home/jenkins/workspace/polkit-qt-1 kf5-qt5 XenialQt5.7/install-prefix/] Notably advantage is that relocation issue get entirely eliminated as the install prefix is always the same, and as an added bonus paths become much shorter and easier to read in the build logs. It also detaches the build tooling from the host tooling. e.g. the build code at this point no longer needs to care about which path Jenkins was installed to, or where it was configured to put workspaces, or what the jenkins job name is, or if jenkins is even still used. Food for thought :) HS
