installing git repository ignores UV_LINK_MODE, breaks on some filesystems

[PhilipVinc]

Summary

I am on a cluster with a distributed filesystem (beefgs) which does not support hard links.
I am trying to install a repository directly, but it fails when symlinking the repository between two locations in the uv cache directory.

I would assume that setting UV_LINK_MODE=symlink or UV_LINK_MODE=copy would fix the error, but it seems that the setting is not applied to the git command in this case

(base) [filippo.vicentini@cholesky-login02 prova2]$ uv init --no-package
Initialized project `prova2`
(base) [filippo.vicentini@cholesky-login02 prova2]$ uv add git+https://github.com/netket/netket
error: Git operation failed
  Caused by: process didn't exit successfully: `/usr/bin/git clone --local /mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/db/292f78b3ecf26bf6 /mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/checkouts/292f78b3ecf26bf6/f1db6bb` (exit status: 128)
--- stdout
Cloning into '/mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/checkouts/292f78b3ecf26bf6/f1db6bb'...

--- stderr
fatal: failed to create link '/mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/checkouts/292f78b3ecf26bf6/f1db6bb/.git/objects/pack/pack-384b576a7a115ef20196172649a6bf2ab2b2ab8e.idx': Operation not permitted
fatal: The remote end hung up unexpectedly
(base) [filippo.vicentini@cholesky-login02 prova2]$ ^C
(base) [filippo.vicentini@cholesky-login02 prova2]$ export UV_LINK_MODE=copy
(base) [filippo.vicentini@cholesky-login02 prova2]$ uv add git+https://github.com/netket/netket
error: Git operation failed
  Caused by: process didn't exit successfully: `/usr/bin/git clone --local /mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/db/292f78b3ecf26bf6 /mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/checkouts/292f78b3ecf26bf6/f1db6bb` (exit status: 128)
--- stdout
Cloning into '/mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/checkouts/292f78b3ecf26bf6/f1db6bb'...

--- stderr
fatal: failed to create link '/mnt/beegfs/home/CPHT/filippo.vicentini/.cache/uv/git-v0/checkouts/292f78b3ecf26bf6/f1db6bb/.git/objects/pack/pack-384b576a7a115ef20196172649a6bf2ab2b2ab8e.idx': Operation not permitted
fatal: The remote end hung up unexpectedly

Platform

Linux 3.10.0-1062.el7.x86_64 x86_64 GNU/Linux

Version

uv 0.5.30

Python version

Python 3.12.7

[charliermarsh]

Hmm, we'll need to decide whether we want to support this. This is a link within the cache, which is not what UV_LINK_MODE is intended to affect.

[PhilipVinc]

I just will point out that this kind of filesystem/restriction is relatively common in academic clusters.
If you do not support this, it becomes impossible to install a git repository, which are very common to keep private research code, and we don't necessarily tag/build wheels (it's very hard to setup a private wheel depot).

I hope you'd consider supporting this in some way, as otherwise we'd be forced to use other tools in academic environments.
I find that uv helps students/researchers have a much more reproducible environment, and save them time, so I would hope I can keep pushing for it (but due to #7642 / #1495 it is hard...).

So please, do support this kind of setups!

[charliermarsh]

I think it makes sense to re-try the operation with --no-hardlinks if it fails.