[locker95]

Summary

With podman, ephemeral builder saves cannot omit base layers the way Docker allows. imgutil falls back to extracting builder layers under /tmp/imgutil.local.image.* and historically never deleted those dirs, so repeated pack build filled /tmp (especially painful when /tmp is on tmpfs).

The cleanup is implemented in imgutil: after Save/SaveFile finish reading extracted base layers, those temp dirs are removed. Layers pack adds on purpose (builder scratch artifacts, daemon/image cache) are not deleted.

• Root fix: local: clean up daemon layer extract dirs after Save imgutil#309
• This PR wires pack to that revision via a temporary replace until Allow attaching pack to network for build and run #309 lands on buildpacks/imgutil. After merge, the replace can be dropped in favor of a normal require bump.

Output

Before

# after pack build with podman
$ ls -d /tmp/imgutil.local.image.*
/tmp/imgutil.local.image.xxx
/tmp/imgutil.local.image.yyy   # accumulates on every build

After

# extract dirs are removed when Save returns
$ ls -d /tmp/imgutil.local.image.*
ls: cannot access '/tmp/imgutil.local.image.*': No such file or directory

Documentation

• Should this change be documented?
  • Yes, see #___
  • No

Related

Resolves #1167
Depends on buildpacks/imgutil#309