cargo package / publish don't handle symlink correctly on Windows

[upsuper]

If you package a crate with symlink, the file would not be followed but be packed as a file with relative path as content. For example, if you checkout serde-rs/serde, and run cargo package in serde directory, the license files in the package directory would only have content like ../LICENSE-APACHE.

It's probably actually a problem of Git for Windows which may not checkout symlink correctly. But maybe Cargo can try harder to query the VCS for whether it's a symlink or not (e.g. use git ls-files -s).

Related issues: alexcrichton/cargo-vendor#77, #3896, #2748.

[alexcrichton]

According to https://stackoverflow.com/questions/5917249/git-symlinks-in-windows this may be an msys/MinGW thing. In that case this may be quite difficult to fix...

[mati865]

Due to permission error (yes, one cannot simply create symlink without admin rights on Windows) ln -s was configured to do copy instead.
See here to disable it.

[Tastaturtaste]

Since I lost some hours today to this problem I want to document what solved this problem for me here.
Basically just follow the instruction in this stackoverflow answer. This will not fix symlinks that are already broken, though maybe another answer or comment there will be helpful.

I will outline the general steps here, too:

1. Enable developer mode or give your account symlink permissions
2. Enable symlinks in git
   • git config core.symlinks should return true in your repo
3. Make sure your global settings are not overwritten by your local settings