Unspecified USER in Dockerfile causes checkouts with 'Permission Denied'

[0xjmux]

Hi, I'm trying to use this to build a package with pyinstaller on a self-hosted runner but am running into some issues.

Since the Dockerfile doesn't specify a USER, the commands in entrypoint.sh are run as root, causing the built artifacts to be owned by root:root (See this discussion post).

This is likely not much of an issue on Github hosted runners since the environment is re-provisioned, but on a self hosted runner after the first run of this action the checkout step fails with:

   warning: failed to remove [REPO]/dist/windows: Permission denied
Warning: Unable to clean or reset the repository. The repository will be recreated instead.
Deleting the contents of '/home/jenkins/gha/w1/w/[REPO]
Error: File was unable to be removed Error: EACCES: permission denied, rmdir '/home/jenkins/gha/w1/w/[REPO]/dist/windows'

Because the built artifacts are in the repo directory, this also causes linux builds of the same source to fail. Specifying a USER in the Dockerfile would be greatly appreciated.

[JackMcKew]

Please feel free to open a PR with the needed change 🙂