Crash when referencing "--action_env" command line option in settings parameter in transition implementation

Description of the bug:

I need to modify the --action_env settings when transitioning, but when I access them in my transition implementation like this

... = settings["//command_line_option:action_env"]

Bazel crashes with this internal error:

Starting local Bazel server and connecting to it...
Loading: 
Loading: 0 packages loaded
FATAL: bazel crashed due to an internal error. Printing stack trace:
net.starlark.java.eval.Starlark$UncheckedEvalException: IllegalArgumentException thrown during Starlark evaluation (//action-env-bug:foo.bzl)
	at <starlark>._foo_transition_impl(/usr/local/google/home/nmosier/tmp/bazel-bug/action-env-bug/foo.bzl:1)
Caused by: java.lang.IllegalArgumentException: invalid Starlark value: class com.google.common.collect.ImmutableEntry
	at net.starlark.java.eval.Starlark.checkValid(Starlark.java:112)
	at net.starlark.java.eval.StarlarkList.checkElemsValid(StarlarkList.java:176)
	at net.starlark.java.eval.StarlarkList.copyOf(StarlarkList.java:170)
	at net.starlark.java.eval.Starlark.fromJava(Starlark.java:188)
	at net.starlark.java.eval.EvalUtils.index(EvalUtils.java:456)
	at net.starlark.java.eval.Eval.evalIndex(Eval.java:718)
	at net.starlark.java.eval.Eval.eval(Eval.java:493)
	at net.starlark.java.eval.Eval.evalBinaryOperator(Eval.java:532)
	at net.starlark.java.eval.Eval.eval(Eval.java:479)
	at net.starlark.java.eval.Eval.evalCall(Eval.java:622)
	at net.starlark.java.eval.Eval.eval(Eval.java:489)
	at net.starlark.java.eval.Eval.exec(Eval.java:271)
	at net.starlark.java.eval.Eval.execStatements(Eval.java:82)
	at net.starlark.java.eval.Eval.execFunctionBody(Eval.java:66)
	at net.starlark.java.eval.StarlarkFunction.fastcall(StarlarkFunction.java:191)
	at net.starlark.java.eval.Starlark.fastcall(Starlark.java:619)
	at com.google.devtools.build.lib.analysis.config.StarlarkDefinedConfigTransition$RegularTransition.evaluate(StarlarkDefinedConfigTransition.java:360)
	at com.google.devtools.build.lib.analysis.starlark.FunctionTransitionUtil.applyAndValidate(FunctionTransitionUtil.java:98)
	at com.google.devtools.build.lib.analysis.starlark.StarlarkRuleTransitionProvider$FunctionPatchTransition.patch(StarlarkRuleTransitionProvider.java:186)
	at com.google.devtools.build.lib.analysis.config.transitions.PatchTransition.apply(PatchTransition.java:75)
	at com.google.devtools.build.lib.analysis.config.transitions.ComposingTransition.apply(ComposingTransition.java:68)
	at com.google.devtools.build.lib.analysis.config.ConfigurationResolver.applyStarlarkTransition(ConfigurationResolver.java:505)
	at com.google.devtools.build.lib.analysis.config.ConfigurationResolver.applyTransitionWithoutSkyframe(ConfigurationResolver.java:440)
	at com.google.devtools.build.lib.skyframe.SkyframeExecutor.getConfigurations(SkyframeExecutor.java:2086)
	at com.google.devtools.build.lib.analysis.config.ConfigurationResolver.getConfigurationsFromExecutor(ConfigurationResolver.java:584)
	at com.google.devtools.build.lib.analysis.AnalysisUtils.getTargetsWithConfigs(AnalysisUtils.java:193)
	at com.google.devtools.build.lib.analysis.BuildView.update(BuildView.java:245)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.runAnalysisPhase(AnalysisPhaseRunner.java:217)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.execute(AnalysisPhaseRunner.java:129)
	at com.google.devtools.build.lib.buildtool.BuildTool.buildTargets(BuildTool.java:198)
	at com.google.devtools.build.lib.buildtool.BuildTool.processRequest(BuildTool.java:443)
	at com.google.devtools.build.lib.buildtool.BuildTool.processRequest(BuildTool.java:411)
	at com.google.devtools.build.lib.runtime.commands.BuildCommand.exec(BuildCommand.java:103)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.execExclusively(BlazeCommandDispatcher.java:585)
	at com.google.devtools.build.lib.runtime.BlazeCommandDispatcher.exec(BlazeCommandDispatcher.java:231)
	at com.google.devtools.build.lib.server.GrpcServerImpl.executeCommand(GrpcServerImpl.java:550)
	at com.google.devtools.build.lib.server.GrpcServerImpl.lambda$run$1(GrpcServerImpl.java:614)
	at io.grpc.Context$1.run(Context.java:579)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

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

action-env-bug.zip

$ unzip action-env-bug
$ cd action-env-bug
$ bazel build bin # SUCCESS
$ bazel build --action_env="X=1" bin # CRASH

Which operating system are you running Bazel on?

Linux (Debian)

What is the output of bazel info release?

release 5.2.0

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

Have you found anything relevant by searching the web?

No response

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

No response

[nmosier]

That’s the same error I get too.

[aiuto]

This may be fixed at head. We’re looking into backporting the fix to 5.x