salt: GITFS w/ pygit2 0.28.2 and a git repo requiring authentication, fails

Description of Issue

I’m running Alpine docker containers. Alpine 3.10 has just been released and pygit2 has been bumped from 0.27.1-r0 to 0.28.2-r0. Now my GITFS repos are failing.

I’m using HTTPS as a transport, but I see the same behaviour using SSH keys.

GitPython does not experience the same issue.

HTTPS

[DEBUG   ] Updating gitfs fileserver cache for the following targets: [('https://git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states', None)]
[DEBUG   ] Re-using gitfs object for process 41
[DEBUG   ] Set update lock for gitfs remote 'https://git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states'
[DEBUG   ] Fetching gitfs remote 'https://git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states'
[DEBUG   ] Removed update lock for gitfs remote 'https://git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states'
[ERROR   ] Exception caught while fetching gitfs remote 'https://git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states': list index out of range
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/salt/utils/gitfs.py", line 2333, in fetch_remotes
    if repo.fetch():
  File "/usr/lib/python3.7/site-packages/salt/utils/gitfs.py", line 767, in fetch
    return self._fetch()
  File "/usr/lib/python3.7/site-packages/salt/utils/gitfs.py", line 1702, in _fetch
    origin = self.repo.remotes[0]
  File "/usr/lib/python3.7/site-packages/pygit2/remote.py", line 582, in __getitem__
    return list(self)[name]
IndexError: list index out of range

SSH

[ERROR   ] Exception caught while fetching gitfs remote 'ssh://#################@git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states': list index out of range
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/salt/utils/gitfs.py", line 2333, in fetch_remotes
    if repo.fetch():
  File "/usr/lib/python3.7/site-packages/salt/utils/gitfs.py", line 767, in fetch
    return self._fetch()
  File "/usr/lib/python3.7/site-packages/salt/utils/gitfs.py", line 1702, in _fetch
    origin = self.repo.remotes[0]
  File "/usr/lib/python3.7/site-packages/pygit2/remote.py", line 582, in __getitem__
    return list(self)[name]
IndexError: list index out of range

Setup

I can reproduce this with a single salt-master and a private git repo. The trigger seems to be the version of pygit2.

gitfs.conf

fileserver_backend:
  - gitfs

gitfs_remotes:
  - https://git-codecommit.ap-southeast-2.amazonaws.com/v1/repos/salt-states:
    - user: ############
    - password: ##########

Steps to Reproduce Issue

The following steps reproduce the issue for me:

docker run -it alpine:3.10
apk add git salt-master
mkdir /etc/salt/master.d
vi /etc/salt/master.d/gitfs.conf
Configure a GITFS with a git repo requring authentication
salt-master -l info

Versions Report

Salt Version:
           Salt: 2019.2.0

Dependency Versions:
           cffi: 1.11.5
       cherrypy: 18.1.1
       dateutil: 2.7.3
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
          ioflo: Not Installed
         Jinja2: 2.10
        libgit2: 0.28.2
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.6.1
   mysql-python: Not Installed
      pycparser: 2.19
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: 0.28.2
         Python: 3.7.3 (default, May  3 2019, 11:24:39)
   python-gnupg: Not Installed
         PyYAML: 5.1.1
          PyZMQ: 18.0.1
           RAET: Not Installed
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.5.2
            ZMQ: 4.3.1

System Versions:
           dist:
         locale: UTF-8
        machine: x86_64
        release: 4.9.0-9-amd64
         system: Linux
        version: Not Installed