Broken symlinks prevent packaging when using `package.include`

[casey]

Problem

Broken symlinks break packaging. This can be fixed by using package.exclude, but package.exclude is mutually exclusive with package.include, so this cannot be fixed if you're already using package.include.

Steps

cargo init foo
cd foo
ln -s foo bar
echo '[package]
name = "cargo-exclude"
version = "0.1.0"
edition = "2021"
include = ["/src"]' > Cargo.toml
git add .
git commit -m 'commit'
cargo package

Possible Solution(s)

Cargo should not follow symlinks that are excluded by virtue of not being included in package.include

Notes

No response

Version

cargo 1.62.1 (a748cf5a3 2022-06-08)
release: 1.62.1
commit-hash: a748cf5a3e666bc2dcdf54f37adef8ef22196452
commit-date: 2022-06-08
host: aarch64-apple-darwin
libgit2: 1.4.2 (sys:0.14.2 vendored)
libcurl: 7.79.1 (sys:0.4.51+curl-7.80.0 system ssl:(SecureTransport) LibreSSL/3.3.6)
os: Mac OS 12.5.0 [64-bit]

[ehuss]

cc @weihanglo This seems to have been introduced by #10214. I think an error like this (particularly not matching the include pattern) probably should be ignored. I'm not sure how tricky it will be to handle this, though.