Consistent Jenkins Gerrit bots?

[Stephan Bergmann]

Seeing the incident around 
<https://gerrit.libreoffice.org/plugins/gitiles/core/+/caabc3f9fc0b7640966bd55ca0a2bc42f255a945%5E%21> 
"external/liborcus: Blind fix attempt for older macOS builds, take 3", I 
wonder whether it would be possible that all the Jenkins bots that build 
a given platform for Gerrit use a sufficiently similar setup?

It is frustrating to see a Gerrit change happen to build green on one 
Jenkins bot, but only to cause unrelated Gerrit changes to fail after it 
has been submitted.  (And sure, we could have reverted the culprit 
commit, but that would have made it much more difficult to come up with 
a fix if you don't have access locally to a setup that exhibits the issue.)