rules_apple reuses artefacts built for different SDK versions

[bgeron]

Today my build broke because of a poisoned cache. With the cache I had, Bazel/rules_apple was trying to reuse build artefacts built with iOS SDK 17.0, while building for iOS SDK 17.2, which failed the build. Rerunning Bazel did not prompt the creation of fixed artefacts for dependencies.

My colleague hit the same issue independently. I couldn't figure out how to clear my Bazel cache selectively to fix this; we both ended up clearing all cache.

We have some upstream dependencies in our tree which have minimum_os_version = "17.0". For our own codebase, we have minimum_os_version = "17.2".

I threw away my logs before my colleague prompted me to make a ticket, so this is all largely from memory. I think this was the sequence of events, with lots of time elapsing between (2) and (3).

1. Upgrade Xcode (to 15.1)
2. Select Xcode15.1 command line tools
3. Build our project with Bazel. This fails at a later stage because minimum_os_version = "17.2" cannot be met.
4. Open Xcode for the first time, to download and install the included iOS 17.2 SDK.
5. Rebuild our project with Bazel.
6. Get an error about not being able to compile with SDK 17.2 against dependency artefacts that were built for SDK 17.0.
7. Remove all Bazel's caches and rebuild. This succeeds.

[brentleyjones]

Were these swiftmodule's that had the incorrect version? If so, I think this might be bazelbuild/rules_swift#1126.

[bgeron]

Yes, they were. Looks like this is a probably duplicate, thanks!