Access workspace status in a Starlark action

[dfabulich]

https://groups.google.com/forum/#!topic/bazel-discuss/hqyMFjEpJgM

There's apparently no way to access volatile-status.txt in a Skylark action.

[dslomov]

@damienmg ptal

[damienmg]

Yes there is no nice way to do it, except use a stamped genrule that expose that file to the skylark rule.

[schroederc]

It's possible to add a dependency to the ctx.version_file artifact and read it (as well as ctx.info_file). However, it would be useful to allow Skylark rules access to value of the --stamp setting so that they can conditionally rely on that file when stamping is requested.

This issue also relates tangentially to #849.

[mgyucht]

+1! I would love to be able to do this as well.

[mikedanese]

Is this even possible with workspace status modeled as an action? What would a solution look like?

[AustinSchuh]

Building off what @schroederc wrote, I'd really love to only stamp when --stamp=true is specified. Which means that I need access to the --stamp flag in skylark.