Currently the build fails with
warning: reject refs/heads/HEAD because shallow roots are not allowed to be updated
error: Could not read 0c2088d438
fatal: Failed to traverse parents of commit ea1803efdc
error: program 'git' failed with exit code 128
Following discussion with Shea and Graham. It's a big enough change
from the last release. Also, from a semver perspective, 2.0 makes more
sense because we did remove some interfaces (like nix-pull/nix-push).