[jrockway]

Bazel prints a message when you invalidate the in-memory cache in a perhaps accidental way; you can supply it with a flag to make this an error and skip the cache invalidation.

If you try to run two Bazel invocations in parallel in the same workspace, one waits for the other to be done.

[jeffbee]

I assumed they meant an error of improperly using cached results. I am sure bazel has its flaws but it assiduously avoids that.

[sunshowers]

I did mean improperly using cached results. It's merely the hardest problem in computer science :)

The sibling suggests this may still be an issue. I'm not surprised—cache invalidation is very difficult to solve, and conservative approximations like tearing down the whole process each time tend to be quite effective.

[__float]

Yes, unless you're using persistent workers. Then you may very well run into the same issues they mention.