Bug(v0.9.0-rc): Downloading modules fails with /tmp on tmpfs

[ngergs]

Bug Report

1. Minimal reproduce step (Required)

Use the kcl cli and have on linux /tmp on a tmpfs (or any filesystem separate from where the cli will be executed)

kcl mod init && kcl mod add k8s

Relevant excerpt from mount:

tmpfs on /tmp type tmpfs (rw,nosuid,nodev,nr_inodes=1048576,inode64)

2. What did you expect to see? (Required)

No error ;)

3. What did you see instead (Required)

adding dependency 'k8s'
downloading 'kcl-lang/k8s:1.30' from 'ghcr.io/kcl-lang/k8s:1.30'
rename /tmp/336415861 /home/ngergs/.kcl/kpm/k8s_1.30: invalid cross-device link

4. What is your KCL components version? (Required)

kcl cli is 0.9.0-rc.1-linux-amd64

5. Error origin

The bug originates from here.

os.Rename is just a thin wrapper around syscall.Rename which errors if source and destination are not on the same filesystem.

Possible quickfixes that I see after glancing over it:

• Initialize the tmp directory next to the destination so that they live on the same filesystem. This however could mean that orphaned files remain in edge case crash scenarios as there is no os cleanup mechanism like for /tmp present.
• Handle the rename error via a errors.Is(syscall.EXDEV) check and fallback to copying. This of course looses the integrity guarantees renaming brings for systems where /tmp is not on the same filesystem.

[Peefy]

Thanks for the feedback. PRs welcome or I'll take it later. ❤