#12130 Determine which files were changed by writing a digest Issue created by Eric-Arellano To land #12129, we need to know which files were changed when writing a digest to the build root, so that we can revert those changes at the end of

./pants run

/

./pants repl

. Some tricky requirements: • It's possible for

./pants run

and

./pants repl

to change files that were changed by writing the digest. That is,

write_digest

changes

f.ext

, then the user's script in

./pants run

changes that file again. We should preserve the users's change and not revert back to the original. • This should be performant. Ideally we do not need to Snapshot the entire repository. •

Workspace.write_digest()

can write to files under

pants_ignore

, e.g. the

dist/

folder. We presumably can't snapshot those files beforehand. pantsbuild/pants