This bitbake commit openembedded/bitbake@457288b seems to break gitpkgv.bbclass here: https://github.com/openembedded/meta-openembedded/blob/master/meta-oe/classes/gitpkgv.bbclass#L83
If your default is BB_GIT_SHALLOW = "1", the bare clone repo will not be created in the "sources/git2" folder (as before) and "gitpkgv.bbclass" always returns None. The path in url.localpath does not exists.
Possible solution is, to force BB_GIT_SHALLOW = "0" in that class:
