When you have an include statement in the user .gitconfig there content will take precedence over the local .git/config of the repository.

E.g. the following code:
entry = repo.config_reader().get_value('gitlab', 'url')

With the following config setup:

~/.gitconfig:

[include]
    path = ~/.gitconfig-local
[gitlab]
    url = url1

~/.gitconfig-local:

[gitlab]
    url = url2

.git/config:

[gitlab]
    url = url3

Will return url2 I would expect to receive url3 instead as local config should take precedence as the include was in a more global config.

Looks like the issue resides inside the read function e.g.

As the function is just to big, I'm not able to provide a fix.

Versions in use:

>>> import git; git.__version__
'2.1.3'

python --version
Python 2.7.13