Jenkins: urgent security upgrade in the Foo module that literally every company 100% depends on!
Foo module: my config file format changed but I’ll automatically upgrade it for you. Uh, I’m not 100% backward compatible (see this bug report written in Linear A for details) so there’s a nonzero chance that I won’t start correctly afterwards and remember I’ll have already rewritten my own config into a format that prior versions can’t parse so go ahead and schedule a post-mortem just in case!