os.environ['GIT_SSH_COMMAND'] = ssh_cmd
However, I cannot use custom_environment or update_environment before instantiating the repo.
I have tried this:
ssh_cmd = 'ssh -i /home/user/.ssh/other_rsa'
repo = Repo()
repo.git.update_environment(GIT_SSH_COMMAND=ssh_cmd)
repo = Repo.clone_from(repo_url, repo_dir)
NOGO - looks for wrong keys
Also:
ssh_cmd = 'ssh -i /home/user/.ssh/other_rsa'
repo = Repo()
with repo.git.custom_environment(GIT_SSH_COMMAND=ssh_cmd)
    repo = Repo.clone_from(repo_url, repo_dir)
NOGO - looks for wrong keys
Also:
ssh_cmd = 'ssh -i /home/user/.ssh/other_rsa'
repo = Repo.clone_from(repo_url, repo_dir, env={'GIT_SSH_COMMAND': ssh_cmd})
NOGO - looks for wrong keys
In the preceding scenarios, I have verified that repo.git.environment() is set correctly, and it still doesn't work.
The only thing that works is:
os.environ['GIT_SSH_COMMAND'] = ssh_cmd
repo = Repo.clone_from(repo_url, repo_dir)
          
This seems to be a usability issue, as Repo.clone_from(repo_url, repo_dir, env={'GIT_SSH_COMMAND': ssh_cmd}) is the one that should work. The others cannot work as Repo.clone_from is a class method, not an instance method.
I do wonder whether you are using the latest version, as judging from the code, the env=... version seems to be implemented correctly.
pip install gitpython
I get 1.0.2. That is odd since I see 2.0.0 is on PyPI, but even doing
pip install GitPython==2.0.0
I get No matching distribution found for GitPython==2.0.0.
When I get a chance I'll install from the repo tag and see if it changes.
          
Thanks for letting me know, it seems we have got a bug at our hands. There is no test for this feature, so it might very well be it's broken. The workaround described here works as the git command will use the current environment as its basis when spawning git commands - good to know that this works at least.
Regarding the installation issue: It should work now. Turns out I managed to not upload the actual file when creating the new release.
Cloning with Specific Private SSH Key
Repo.clone_from(env=...) doesn't have the desired effect
    Apr 22, 2016
          
I'm having [what I believe to be] the same issue on GitPython 2.0.2, but the workaround isn't working for me either.
key_path = '/over/the/rainbow'
repo_path = '[email protected]:foo/bar.git'
repo = Repo.init(repo_path)
origin = repo.create_remote('origin', url)
ssh_cmd = 'ssh -i ' + keypath
with repo.git.custom_environment(GIT_SSH_COMMAND=ssh_cmd):
    os.environ['GIT_SSH_COMMAND'] = ssh_cmd
    print("GIT_SSH_COMMAND='" + ssh_cmd + '' git clone ' + url)
    repo.remotes.origin.fetch()
This returns:
GIT_SSH_COMMAND='ssh -i /over/the/rainbow' git clone [email protected]:foo/bar.git
Traceback (most recent call last):
  File "/opt/champagne/lib/main.py", line 35, in <module>
    repo.remotes.origin.fetch()
  File "/usr/local/lib/python3.4/dist-packages/git/remote.py", line 657, in fetch
    res = self._get_fetch_info_from_stderr(proc, progress or RemoteProgress())
  File "/usr/local/lib/python3.4/dist-packages/git/remote.py", line 556, in _get_fetch_info_from_stderr
    raise GitCommandError(("Error when fetching: %s" % line,), 2)
git.exc.GitCommandError: 'Error when fetching: fatal: Could not read from remote repository.
Strangely enough, running GIT_SSH_COMMAND='ssh -i /over/the/rainbow' git clone [email protected]:foo/bar.git by itself works perfectly though. Weird, right?
          
Try using only the os.environ setting. Doing so inside of the custom environment may be superseding your environment variable by passing it to the command.
key_path = '/over/the/rainbow'
repo_path = '[email protected]:foo/bar.git'
repo = Repo.init(repo_path)
origin = repo.create_remote('origin', url)
ssh_cmd = 'ssh -i ' + keypath
os.environ['GIT_SSH_COMMAND'] = ssh_cmd
print("GIT_SSH_COMMAND='" + ssh_cmd + '' git clone ' + url)
repo.remotes.origin.fetch()
          
This is an odd one - I checked the code-path it is taking and could only see that it looks alright: The git process is always started with a customized environment, based on os.environ, with all custom environment variables added to it.
As you shouldn't have to change os.environ directly to influence command execution, something you might try to learn more about the issue is to add a line line this right after this line:
import pprint
pprint.pprint(env)
This should make clear which environment is actually passed to help understanding what is going on here.
logging.basicConfig(level=logging.INFO)
os.environ['GIT_PYTHON_TRACE']='1'
os.environ['GIT_SSH_COMMAND']='ssh -i /tmp/id_rsa'
repo = Repo.clone_from('[email protected]:config/config.git', 'aabb',env={'GIT_SSH_COMMAND':'ssh -i /tmp/id_rsa'})
this code doesn't work and doesn't hava debug log
          
@woshihaoren I think what could work here is if you would import git after setting the environment variables, or by setting the environment variables from the shell invoking the python interpreter. Reason for that is that the environment variable is only read once at the time of import, and then cached in a similarly named class variable in the Git type.
Thank you , It's OK, and git version need >=2.3  GIT_SSH_COMMAND can work

import os
import logging
logging.basicConfig(level=logging.INFO)
os.environ['GIT_PYTHON_TRACE']='1'
from git import Repo
Repo.clone_from('[email protected]:config/config.git', 'aabb',env={'GIT_SSH_COMMAND':'ssh -i /tmp/id_rsa'})