Why can't Git resolve remote branches when --single-branch is used?

问题:

So, we frequently optimize clones by effectively cloning with --single-branch. However, we are then unable to get additional branches later. What is the difference, plumbing-wise, between a git clone with and without --single-branch? How can we fetch down additional branches later?

A standard clone:

$ git clone -b branch-name https://repo.url standard $ cd standard $ git checkout remote-branch Branch 'remote-branch' set up to track remote branch 'remote-branch' from 'origin'. Switched to a new branch 'remote-branch' 

A single-branch clone:

$ git clone -b branch-name --single-branch https://repo.url singlebranch $ cd singlebranch $ git checkout remote-branch error: pathspec 'remote-branch' did not match any file(s) known to git 

UPDATE

Per the answer from @AndrewMarshall, below, you need to update the default fetch refspec in the config. Even though you can hack your way around the fetch to pull down the right commits, your attempted checkout will absolutely deny knowing anything about that branch if you don't fix your config first:

$ git fetch origin +refs/heads/remote-branch:refs/remotes/origin/remote-branch From https://gerrit.magicleap.com/a/platform/mlmanifest  * [new branch]      remote-branch -> origin/remote-branch  $ git checkout remote-branch  error: pathspec 'remote-branch' did not match any file(s) known to git  $ git remote set-branches origin --add remote-branch $ git checkout remote-branch  Branch 'remote-branch' set up to track remote branch 'remote-branch' from 'origin'. Switched to a new branch 'remote-branch' 

Notice we fetch it, then reconfigure, then checkout. The fetch can happen in any order (though you have to pass parameters if not in the config) but the checkout is gated by the config.

回答1:

--single-branch works by setting the remote’s fetch property to only be the single branch name, instead of a glob:

$ git config --get-all remote.origin.fetch +refs/heads/master:refs/remotes/origin/master 

So let’s add an entry with git remote set-branches:

$ git remote set-branches origin --add other-branch $ git config --get-all remote.origin.fetch     +refs/heads/master:refs/remotes/origin/master +refs/heads/other-branch:refs/remotes/origin/other-branch  $ git fetch From origin  * [new branch]      other-branch        -> origin/other-branch  $ git checkout other-branch Branch 'other-branch' set up to track remote branch 'other-branch' from 'origin'. Switched to a new branch 'other-branch' 

Or, alternatively, make it a glob so all branches may be fetched (the default, non-single-branch behavior):

git remote set-branches origin '*' 

文章来源: Why can't Git resolve remote branches when --single-branch is used?