Repository object init with literal GIT_DIR

Consider the following corner case:

ben@f1:/tmp$ git init --bare weird.git
Initialized empty Git repository in /tmp/weird.git/                                              
ben@f1:/tmp$ cd weird.git
ben@f1:/tmp/weird.git$ git init --bare .git
Initialized empty Git repository in /tmp/weird.git/.git/                                         
ben@f1:/tmp/weird.git$ git rev-parse --git-dir
.git
ben@f1:/tmp/weird.git$ GIT_DIR="./" git rev-parse --git-dir                                      
./
ben@f1:/tmp/weird.git$ python3 -c 'import pygit2; print(pygit2.Repository("./"))'                
pygit2.Repository('/tmp/weird.git/.git/')
ben@f1:/tmp/weird.git$ GIT_DIR=./ python3 -c 'import pygit2; print(pygit2.Repository("./"))'     
pygit2.Repository('/tmp/weird.git/.git/')

It's possible to use git to work on the repo with GIT_DIR="/tmp/weird.git".

How can I use pygit2 to work on the same repo ("/tmp/weird.git") and not the other repo in "/tmp/weird.git/.git"? Essentially, I'd like to init a pygit2.Repository object with a literal GIT_DIR, without performing repository discovery.

Start at the pygit2.Repository initialization entry point and compare its handling of "./" with Git's literal GIT_DIR behavior. Check the available libgit2 repository-opening behavior before deciding how a literal path should be represented. Done means a Repository can target /tmp/weird.git without discovering /tmp/weird.git/.git, with coverage for this nested-repository case.