Problem
If CARGO_TARGET_DIR is set to a path that is a symlink, or target itself is a symlink, cargo clean will delete the symlink and not anything in the linked directory.

Steps

1. mkdir foo
2. ln -sfn foo target
3. cargo build
4. cargo clean
5. ls foo
6. ls target

Expected: foo should be empty, target should still point to foo
Actual: foo has all build artifacts, target has been removed.

Possible Solution(s)
If cargo's target directory is a symlink, it should remove the contents of the symlink rather than the symlink itself.

Output of cargo version:
cargo 1.38.0 (23ef9a4 2019-08-20)