Or you could cache the solve, surely? Simply explicitly including your transitive dependencies and pinning everything should do the trick - but there is work being done actively on a lockfile standard, it's just the sort of topic that attracts ungodly amounts of bikeshedding.

(One of these days I'll have to figure out this "CI" thing. But my main focus is really just solving interesting programming problems, and making simple elegant tools for mostly-small tasks.)