y'know, preparing for a colleague's vacation is a lot like QA testing. you prepare for all likely scenarios, but the moment they're out the door that exception with 0.0001% likeliness of occurring comes to bite you in the ass

Dev 1: "I'll get some time off the next 2 weeks, can you maintain my CI while I am away. I don't think anything should break."

Dev 2: "Sure, don't worry about it."

*jenkins CI proceeds to break during the weekend, dev 2 gets back to work monday morning*

Dev 2: "Oh well shit happens, I'll look at the job and logs, see what happened."

*queues in PMs asking to release a patch tomorrow and turns out the CI is a 5k LoC jenkins groocy script calling nested shell scripts calling ant calling java executables configured with 87 parameters at run time.*

Dev 2: "FUUUUUUUUUUUUUUUUU..."

@PepeTheFrog exactly