Cargo fails to update force-pushed git repositories when git-fetch-with-cli is enabled

[sfackler]

Problem
When using the git-fetch-with-cli configuration option, Cargo will fail to update the a repository if it has been force-pushed:

$ cargo update
    Updating git repository `file:///Users/sfackler/bar`
error: failed to load source for a dependency on `bar`

Caused by:
  Unable to update file:///Users/sfackler/bar

Caused by:
  failed to fetch into /Users/sfackler/.cargo/git/db/bar-399b59269c932c61

Caused by:
  process didn't exit successfully: `git fetch --tags --quiet --update-head-ok 'file:///Users/sfackler/bar' 'refs/heads/*:refs/heads/*'` (exit code: 1)

Here I used a local git repository for simplicity, but a remote one behaves the same way.

Cargo appears to throw away git's output, unfortunately. Weirdly enough, manually running the failing command in the fetch directory succeeds but cargo update continues to fail afterwards. Deleting the fetch directory does make things work though.

Steps

1. Make a crate with a git dependency.
2. Run cargo generate-lockfile.
3. Force-push to the dependency's git repository.
4. Run cargo update.

Notes

cargo 1.33.0 (f099fe94b 2019-02-12)
git version 2.21.0
Darwin sfackler51-mac 17.7.0 Darwin Kernel Version 17.7.0: Thu Dec 20 21:47:19 PST 2018; root:xnu-4570.71.22~1/RELEASE_X86_64 x86_64