berks install fails to fetch git repository dependencies that use git-lfs

[maoe]

We have a Chef cookbook that uses git-lfs to store some binaries. If we depend on it from other cookbooks, berkshelf fails to fetch it during berks install like this:

Fetching 'some-cookbook' from git@git.example.com:chef/some-cookbook.git (at master)
Git error: command `git reset --hard 977350841d8984d56feb3b98faed6a86b22efb79` failed. If this error persists, try remo
ving the cache directory at '/home/maoe/.berkshelf/.cache/git/e41334cf49b248784779d83338e08899eee8ef5d'.Output from the
 command:


hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.
Downloading files/default/some-binary.ubuntu-16.04 (152 MB)

hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.
Error downloading object: files/default/some-binary.ubuntu-16.04 (d297b69): Smudge error: Error downloading files/default/some-binary.ubuntu-16.04 (d297b6970253e17f5e835261ca7645d364a0a23cd73b25ad30ae1f3e4c6fd506): batch request: missing protocol: "file:///home/maoe/.berkshelf/.cache/git/e41334cf49b248784779d83338e08899eee8ef5d/.git/info/lfs"

Errors logged to /tmp/d20190917-15282-4oev7p/.git/lfs/logs/20190917T111501.394111993.log
Use `git lfs logs last` to view the log.
error: external filter 'git-lfs filter-process' failed
fatal: files/default/some-cookbook.ubuntu-16.04: smudge filter lfs failed

        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/mixin/git.rb:24:in `git'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/locations/git.rb:57:in `block in install'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/locations/git.rb:55:in `chdir'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/locations/git.rb:55:in `install'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/installer.rb:193:in `block in download_locations'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/installer.rb:190:in `each'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/installer.rb:190:in `download_locations'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/installer.rb:160:in `install_from_universe'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/installer.rb:43:in `run'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/berksfile.rb:405:in `install'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/cli.rb:131:in `install'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor/command.rb:27:in `run'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor/invocation.rb:126:in `invoke_command'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor.rb:387:in `dispatch'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/cli.rb:47:in `dispatch'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/thor-0.20.3/lib/thor/base.rb:466:in `start'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/lib/berkshelf/cli.rb:23:in `execute!'
        /opt/chefdk/embedded/lib/ruby/gems/2.5.0/gems/berkshelf-7.0.7/bin/berks:5:in `<top (required)>'
        /usr/bin/berks:306:in `load'
        /usr/bin/berks:306:in `<main>'

Apparently this happens because berkshelf clones a bare repository as a cache and clone it to another workspace locally, but unfortunately git-lfs doesn't support fetching from local repositories so git reset --hard #{@revision} fails with the error messages above.

I guess we can do either of the following:

• Use git %{clone --no-checkout --reference="#{cache_path}" #{url} "#{scratch_path}"}
  • This way the origin would be set to url instead of cache_path. It could be slower though.
• Check if the repository uses git-lfs somehow. If so skip caching.
  • I'm not sure how to check it though.

What do you think? If the former sounds good I can make a patch.

FWIW I'm using berkshelf 7.0.7 on Ubuntu.