libgit2 does not seem to handle AOSP manifest repositories.
I experienced the issue both with gitg which used libgit2, and with the lg2 example command.
Reproduction steps
$ cd /tmp
$ mkdir AOSP
$ cd AOSP
$ repo init -u https://android.googlesource.com/platform/manifest -b main
Downloading Repo source from https://gerrit.googlesource.com/git-repo
repo has been initialized in /tmp/AOSP
$ cd .repo/manifests
$ /tmp/examples/build/lg2 status
Unable to open repository '%s' '.' [-1] - unsupported extension name extensions.preciousobjects
$ gitg
Error: not able to open repository “unsupported extension name extensions.preciousobjects”.
Expected behavior
libgit2 is able to open the repo and list all the branches and commits.
Actual behavior
libgit2 fails to open the repository with the following error:
Unable to open repository '%s' '.' [-1] - unsupported extension name extensions.preciousobjects
Version of libgit2 (release number or SHA1)
1.7.2
Operating system(s) tested
Debian Unstable / Linux