Permission error when packing to squashfs file on Linux

[Kirill888]

Checklist

• I added a descriptive title
• I searched open reports and couldn't find a duplicate

What happened?

While running command like this

conda pack --format=squashfs -n test-env 

Things break when copying activate script over into temp location, this happens when

1. Conda is installed by root
2. Temp folder is on the same disk as conda

When creating temp copy of the environment squashfs plugin prefers to use hard-links when copying files on Linux

conda-pack/conda_pack/formats.py

Lines 439 to 443 in fcba5e0

	same_device = os.lstat(source).st_dev == os.lstat(os.path.dirname(target_abspath)).st_dev
	if same_device:
	copy_func = partial(os.link, follow_symlinks=False)
	else:
	copy_func = partial(shutil.copy2, follow_symlinks=False)

but this doesn't work when source file is not owned by the user running conda pack. This is the case when conda-pack is installed by root in base environment, while user running the packing is not root

conda-pack/conda_pack/formats.py

Line 458 in fcba5e0

copy_func(source, target_abspath)

Traceback (most recent call last):
  File "/opt/conda/lib/python3.10/site-packages/conda_pack/cli.py", line 157, in main
    pack(name=args.name,
  File "/opt/conda/lib/python3.10/site-packages/conda_pack/core.py", line 542, in pack
    return env.pack(output=output, format=format,
  File "/opt/conda/lib/python3.10/site-packages/conda_pack/core.py", line 386, in pack
    packer.finish()
  File "/opt/conda/lib/python3.10/site-packages/conda_pack/core.py", line 1142, in finish
    self.archive.add(source, target)
  File "/opt/conda/lib/python3.10/site-packages/conda_pack/formats.py", line 247, in add
    self._add(source, target)
  File "/opt/conda/lib/python3.10/site-packages/conda_pack/formats.py", line 487, in _add
    copy_func(source, target_abspath)
PermissionError: [Errno 1] Operation not permitted: '/opt/conda/lib/python3.10/site-packages/conda_pack/scripts/posix/activate' -> '/tmp/tmp9x4imir_/bin/activate'

in the above copy_func is partial(os.link, follow_symlinks=False). os.link should be used only when source and destination share:

1. same device
2. same owner (st_uid)

Conda Info

No response

Conda Config

No response

Conda list

No response

Additional Context

No response

[github-actions]

Hi there, thank you for your contribution!

This issue has been automatically marked as stale because it has not had recent activity. It will be closed automatically if no further activity occurs.

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Thanks!

[Kirill888]

issue remains with current code in main branch, hard-linking with ownership change is not possible and code assumes that conda is installed as the user running conda-pack.