fix: copy_dir and copy_file to preserve symlinks instead of following them.
#4671
Conversation
Previously, copy_dir would follow symlinks and copy the target contents. Now it preserves symlinks by reading the link target and creating a new symlink with the same target. Adds regression test copy_dir_preserves_symlinks.
Previously, copy_file created a symlink pointing to the source path rather than preserving the original symlink's target. Now it reads the link target and creates a symlink with that same target. Adds regression test copy_file_preserves_symlinks.
cachebag
force-pushed
the
preserve-symlinks
branch
from
7ce58b5 to
5460b37
Compare
|
Thanks for making this patch! Reasonable support for external packagers are still expected, and whether a manual setup is required is largely based on the packagers' opinion: https://rust-lang.github.io/rustup/installation/other.html#using-a-package-manager I have the feeling that we need to somehow support both cases based on whether that's copying the original binary or not... |
There was a problem hiding this comment.
Do you have a specific use case where rustup is not working as you'd expect, which this PR allows to fix?
If you can find such a case, I agree with using this new implementation except for this:
Line 845 in 3382f6f
#1521 is probably too widespread as a fix, and it makes perfect sense to use different copy implementations during self installation and during toolchain installation.
Suggest refining the test cases accordingly if going this way.
| let dest = dest.join(entry.file_name()); | ||
| if kind.is_dir() { | ||
| copy_dir(&src, &dest)?; | ||
| let src_path = entry.path(); |
There was a problem hiding this comment.
Nit: src and dest bindings in the loop body are preventing the input params from being used. Thus, I don't see a very convincing reason to rename them here.
I don't, and I only encountered this looking at the code. It's my understanding that copying symlinks breaks their identity and can cause software to load libraries twice (like the crash that was fixed ad-hoc above). It's also just correct behavior afaik;
I would agree with this and will adjust, so long as you think it's a reasonable patch. I figured at the least I could flag this to note the variance in functionality for copy's. |
2 participants
This PR employs symlink preservation in
copy_fileand adds it tocopy_dir.PR #1504 added symlink preservation to fix crashes in lldb-preview, which contains internal symlinks (liblldb was loading twice due to broken symlinks). Then, PR #1521 later changed
copy_fileto create symlinks pointing to the source path (for Homebrew integration), which may have regressed #1504.This PR restores #1504's behavior: read the symlink target and preserve it. What I'm curious about is what the intended behavior for #1521 was because shouldn't users be able to run
rustup-init --no-self-update? Is that not the recommended way to managerustupvia external package managers?If this PR steers out of scope of the goals of
rustupI'm happy to close it but I feel like the former behavior is preferable for most use cases.