Crash when using exec transition as incoming rule transition

[katre]

Reproduce:

def _impl(ctx):
    pass

demo = rule(
    implementation = _impl,
    cfg = config.exec(),
)

Error:

FATAL: bazel crashed due to an internal error. Printing stack trace:
java.lang.ClassCastException: class com.google.devtools.build.lib.packages.AutoValue_RuleTransitionData cannot be cast to class com.google.devtools.build.lib.packages.AttributeTransitionData (com.google.devtools.build.lib.packages.AutoValue_RuleTransitionData and com.google.devtools.build.lib.packages.AttributeTransitionData are in unnamed module of loader 'app')
	at com.google.devtools.build.lib.analysis.config.ExecutionTransitionFactory.create(ExecutionTransitionFactory.java:39)
	at com.google.devtools.build.lib.analysis.config.TransitionResolver.applyTransitionFromFactory(TransitionResolver.java:114)
	at com.google.devtools.build.lib.analysis.config.TransitionResolver.applyRuleTransition(TransitionResolver.java:99)
	at com.google.devtools.build.lib.analysis.config.TransitionResolver.evaluateTransition(TransitionResolver.java:83)
	at com.google.devtools.build.lib.analysis.AnalysisUtils.targetsToDeps(AnalysisUtils.java:203)
	at com.google.devtools.build.lib.analysis.AnalysisUtils.getTargetsWithConfigs(AnalysisUtils.java:191)
	at com.google.devtools.build.lib.analysis.BuildView.update(BuildView.java:244)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.runAnalysisPhase(AnalysisPhaseRunner.java:217)
	at com.google.devtools.build.lib.buildtool.AnalysisPhaseRunner.execute(AnalysisPhaseRunner.java:129)

(This is copied from an internal bug report)