Though the refspec isn't the first thing that comes to mind when thinking about the Git configuration, it is actually quite close. In a lot of the Git commands, the refspec is used, but often implicitly, that is, the refspec is taken from the configuration file. If you don't remember setting a refspec configuration, you are probably right, but if you cloned the repository or added a remote, you'll have a section in .git/config that looks something like the following (this is for the jgit repository):
[remote "origin"] url = https://git.eclipse.org/r/jgit/jgit fetch = +refs/heads/*:refs/remotes/origin/*
The fetch line contains the configured refspec to fetch in relation to this repository.
