Greg

Aside from the implementation, what use case are you trying to solve?

Either! I'm wondering if other Starlark tricks could also fulfill it.

I want to signal boost https://groups.google.com/g/bazel-discuss/c/vgn9uyyIrIM/m/4trNkRS0AQAJ - @moroten 's discussion listed above The biggest challenge is addressing correctness concerns. Partial approaches could be viable, with [trim_test_configuration](https://github.com/bazelbuild/bazel/blob/3a8d07d0e53742ce7937b332b09191cf83d4083b/src/main/java/com/google/devtools/build/lib/analysis/test/TestConfiguration.java#L133) as precedent.

We can see two improvements to this: - Depending on which flags you change, we think we can easily avoid redoing the exec-configured part of the cache, which can be...

Since this issue is specifically about `--define` and `--test_env`, two more things: - @fmeum did some work to optimize `--test_env`: https://github.com/bazelbuild/bazel/issues/7450 - @fmeum 's considering optimizations for Starlark flags as...

Just to be clear, who still cares about this beside @pauldraper , @tpudlik , and @matts1 ? These comments span over a few years.

> Depending on which flags you change, we think we can easily avoid redoing the exec-configured part of the cache, which can be half the cache for many builds. --define...

Thanks for testing, @keith . Which flags did you toggle? I forgot there's another important difference. That change only applies to flags that don't propagate from the target to exec...

https://github.com/bazelbuild/bazel/issues/24751#issuecomment-2552345553 also mentions this. I tried fixing that instance and ran into some trouble. Let me recall what happened and where this was at...

The challenge is while `--host_cpu` is considered a deprecated part of the pre-platforms API, it still auto-sets to the host machine in a way builds can check directly. There's no...