Hello,
I've faced an issue while trying to use a non-default .gitconfig file
via specifying
GIT_CONFIG environment variable.
What did you do before the bug happened? (Steps to reproduce your issue)
```
# use custom .gitconfig via GIT_CONFIG envvar:
mkdir -p /tmp/git-test/repo
cat <<EOT > /tmp/git-test/.gitconfig
[user]
name = John Doe
email = john@xxxxxx
EOT
cd /tmp/git-test/repo
git init
export GIT_CONFIG=/tmp/git-test/.gitconfig
echo Hi > readme.txt
git add readme.txt
git commit -m 'Initial commit'
```
What did you expect to happen? (Expected behavior)
Git creates a new commit.
What happened instead? (Actual behavior)
Error occurred:
```
Author identity unknown
*** Please tell me who you are.
Run
git config --global user.email "you@xxxxxxxxxxx"
git config --global user.name "Your Name"
to set your account's default identity.
Omit --global to set the identity only in this repository.
fatal: unable to auto-detect email address (got 'john@computer.(none)')
```
What's different between what you expected and what actually happened?
For some reason `git commit` doesn't use configuration options specified
in the
custom `.gitconfig` file.
Anything else you want to add:
`git config` shows correct values:
```
sh-5.1$ pwd
/tmp/git-test/repo
sh-5.1$ echo $GIT_CONFIG
/tmp/git-test/.gitconfig
sh-5.1$ cat $GIT_CONFIG
[user]
name = John Doe
email = john@xxxxxx
sh-5.1$ git config user.name
John Doe
sh-5.1$ git config user.email
john@xxxxxx
```
The same happens with git version 2.32.0.432.gabb21c7263
[System Info]
git version:
git version 2.32.0
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
uname: Linux 5.12.15-arch1-1 #1 SMP PREEMPT Wed, 07 Jul 2021 23:35:29
+0000 x86_64
compiler info: gnuc: 11.1
libc info: glibc: 2.33
$SHELL (typically, interactive shell): /bin/zsh
