Stage a cross-filesystem copy in a private directory instead of deleting a
pre-existing PATH.partial, reject destinations inside the overlay work
directory, save the new path before deleting the old prefix, and verify that
the target keeps user.* xattrs before and after copying. Add tests.
Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
The prefix holds the installed clients and game (about 40 GB). The Nix
launcher always exported DPREFIX=${DPREFIX:-~/.darling}, so the prefix saved
in build/config.json was never used and the only way to move it was an
environment variable in every launch context.
- The launcher uses DPREFIX if set, then the saved prefix, then ~/.darling.
- darling-lol --set-prefix PATH runs scripts/nix-prefix.py in the namespace,
whose root owns the prefix files, so cp -a keeps their owners and xattrs.
It renames the prefix when possible; across filesystems it copies to
PATH.partial and removes the old prefix and its overlay work directory
only after the copy completes. A PATH that already holds a Darling prefix
is used as it is. It refuses non-empty directories that are not prefixes,
nested paths and paths with commas or colons (overlayfs separators), then
saves the path with configure.py --prefix.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
