Description of the problem / feature request:

Rule should be able to detect host/exec config

Feature requests: what underlying problem are you trying to solve with this feature?

Specifically, skipping --stamp behavior in host/exec config, and essentially reimplementing isToolConfig() from <can't remember the Java class in Bazel>

What operating system are you running Bazel on?

Linux

What's the output of bazel info release?

n/a

Have you found anything relevant by searching the web?

Closest related I could find are:

• 11164: starlark observing --stamp value
• Internal FR 170920173 (allow aspects to detect host/exec mode)

Today, this can be worked around by looking at ctx.bin_dir.path. For host most, it'll contain /host/, and exec mode will contain -exec-, but both of these seem like fragile ways to detect the config.