anlambert@carnavalet:/tmp$ python3
Python 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import dulwich
>>> dulwich.__version__
(0, 20, 35)
>>> from dulwich.porcelain import clone
>>> clone("https://forge.softwareheritage.org/source/swh-loader-core.git")
Enumerating objects: 12296, done.
Counting objects: 100% (12296/12296), done.
<Repo at 'swh-loader-core.git'>/5479)
Compressing objects: 100% (5479/5479), done.
Total 12296 (delta 8624), reused 9204 (delta 6364), pack-reused 0
>>> 
anlambert@carnavalet:/tmp$ pip install --upgrade dulwich
Requirement already satisfied: dulwich in /home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages (0.20.35)
Collecting dulwich
  Downloading dulwich-0.20.37-cp39-cp39-manylinux_2_5_x86_64.manylinux1_x86_64.manylinux_2_12_x86_64.manylinux2010_x86_64.whl (551 kB)
     ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 551.8/551.8 kB 9.7 MB/s eta 0:00:00
Requirement already satisfied: urllib3>=1.24.1 in /home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages (from dulwich) (1.26.9)
Requirement already satisfied: certifi in /home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages (from dulwich) (2021.10.8)
Installing collected packages: dulwich
  Attempting uninstall: dulwich
    Found existing installation: dulwich 0.20.35
    Uninstalling dulwich-0.20.35:
      Successfully uninstalled dulwich-0.20.35
Successfully installed dulwich-0.20.37
anlambert@carnavalet:/tmp$ rm -rf swh-loader-core.git/
anlambert@carnavalet:/tmp$ python3
Python 3.9.2 (default, Feb 28 2021, 17:03:44) 
[GCC 10.2.1 20210110] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import dulwich
>>> dulwich.__version__
(0, 20, 37)
>>> from dulwich.porcelain import clone
>>> clone("https://forge.softwareheritage.org/source/swh-loader-core.git")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/porcelain.py", line 443, in clone
    return client.clone(
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/client.py", line 620, in clone
    result = self.fetch(path, target, progress=progress, depth=depth)
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/client.py", line 697, in fetch
    result = self.fetch_pack(
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/client.py", line 2073, in fetch_pack
    refs, server_capabilities, url = self._discover_references(
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/client.py", line 1949, in _discover_references
    [pkt] = list(proto.read_pkt_seq())
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/protocol.py", line 287, in read_pkt_seq
    pkt = self.read_pkt_line()
  File "/home/anlambert/.virtualenvs/swh/lib/python3.9/site-packages/dulwich/protocol.py", line 232, in read_pkt_line
    raise HangupException()
dulwich.errors.HangupException: The remote server unexpectedly closed the connection.
>>>