common does not work with flag_alias

[luispadron]

Description of the bug:

Using the new common in a .bazelrc with flag_alias returns the following error:

ERROR: /Users/<user>/Development/cash-ios/.bazelrc: "common --flag_alias=build_config=//:build_config" disallowed. --flag_alias only supports the "build" command.

Which category does this issue belong to?

CLI, Configurability

What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

• Create a custom config_setting
• Create a .bazelrc
• Attempt to add a flag alias with the common command

common --flag_alias=release_variant=//:release_variant

Which operating system are you running Bazel on?

macOS

What is the output of bazel info release?

release 6.3.2

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse master; git rev-parse HEAD ?

No response

Is this a regression? If yes, please try to identify the Bazel commit where the bug was introduced.

No response

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

Not entirely sure if this is expected but it feels like its not given how common works for other flags.

[katre]

Which commands besides build (and its logical descendents, like test and cquery) do you think need support for --flag_alias?

[luispadron]

Which commands besides build (and its logical descendents, like test and cquery) do you think need support for --flag_alias?

For our use case, none and I'm not sure where it might be useful in other commands. I was just basing this off of how common seems to be working for us with other flags. We've been able to replace usage of build in bazelrc with common except for this case.

[katre]

The code that checks this is in BlazeOptionHandler, and the tests are in starlark_configurations_test.sh.

The test makes it look like this is deliberate, and @gregestren added the check that it isn't supported for test, so I'm going to assign to him for further triage.

[katre]

I'm also re-classifying this as a Feature Request instead of a Bug, since the behavior seems to be intentional.

[luispadron]

Thats fair, I was considering this a bug based on this: #3054

[gregestren]

329b22a is the original change.

The intention was to not allow flag alias definitions for subsets of build (like test). Motivated specifically by CI systems that start with a $ bazel canonicalize-flags to vet flags. canonicalize-flags itself is a subset of build and any setting has to be reflected there

common goes the other way up the inheritance tree and sounds safe to me.

[gregestren]

This is basically a lowest common ancestor problem.

We can only apply flag alias definitions on nodes in canonicalize-flags's ancestor path.

[iancha1992]

A fix for this issue has been included in Bazel 7.0.0 RC5. Please test out the release candidate and report any issues as soon as possible. Thanks!