git aliases causing "Permission denied" error

Question

The following commands

$ git co -b newbranch
$ git co oldbranch

result in "fatal: cannot exec 'git-co': Permission denied" error.

In the same time,

$ git checkout -b newbranch
$ git checkout oldbranch

and

$ sudo git co -b newbranch
$ sudo git co oldbranch

work as expected. Ownership rights for the .git folder are set for the user owning the home folder and 0755/0644 are the mode for .git folder/subfolder/files. There are no git-co script anywhere in the system (that is an expandable alias to git-checkout, which resides in /usr/libexec/git-core` dir).

Aliases are defined in .gitconfig of the home folder:

[alias]
co = checkout

There is no difference in git config -l output for root or unprivileged user. Still sudo git co oldbranch works and git co oldbranch does not.

What am I missing?

Gentoo / kernel 3.0.6 / git 1.7.3.4

Answer 1

The correct answer to this was actually different. Before git runs the aliases it checks the $PATH. In case the directory does not exist, or lacks permissions, git produces the "fatal: cannot exec 'git-co': Permission denied". It does not ever comes to check the aliases so git foobar will produce the same error.

Good people from the git mailing list also reminded me of an strace tool, that can help finding the entry that is returning EACCES, as in: strace -f -e execve git foobar

The credit goes to Jeff King from the git mailing list. :)

Answer 2

Is it possible you have inadvertently created a non-executable git-co file somewhere? I can recreate your situation if I do just that, as demonstrated below.

$ git --version
git version 1.7.7.1.475.g997a1
$ git config --get-regexp '^alias\.co$'
alias.co checkout
$ git co b1
Switched to branch 'b1'
$ touch $HOME/bin/git-co
$ ls -al $HOME/bin/git-co
-rw-r--r-- 1 user user 0 2011-11-03 12:59 /home/user/bin/git-co
$ git co master
fatal: cannot exec 'git-co': Permission denied
$ for p in $(echo "$PATH" | sed -e 's/:/ /g'); do if [ -f "${p}/git-co" ]; then echo "Found git-co in ${p}"; fi; done
Found git-co in /home/user/bin
$ rm $HOME/bin/git-co
rm: remove regular empty file `/home/user/bin/git-co'? y
$ git co master
Switched to branch 'master'

Another thing you might want to try is enabling trace logging to get more information about what Git is doing. Following is an example:

GIT_TRACE=$HOME/trace.log git co master

You must use absolute paths if you want to send output to a file. Otherwise, use true or 1 to send output to standard error; e.g. GIT_TRACE=1. The trace.log file contains:

trace: exec: 'git-co' 'master'
trace: run_command: 'git-co' 'master'
trace: alias expansion: co => 'checkout'
trace: built-in: git 'checkout' 'master'

If you do not see the trace: alias expansion: co=> 'checkout' trace log output, Git is finding a git-co file in the PATH environment variable. Git uses a PATH as follows:

1. Start with an empty PATH, saving any "old" PATH for reference.
2. If the --exec-path=<my git commands path> Git option is found, append <my git commands path> to the PATH.
3. If --exec-path=<my git commands path> was not found and the GIT_EXEC_PATH environment variable is set, append this to the PATH.
4. If you called git using a relative or absolute path, append the absolute path of the git executable to the PATH.
5. If PATH was previously defined, append it to the PATH.
6. If PATH was not previously defined, append /usr/local/bin:/usr/bin:/bin to the PATH.

You can use another alias to get Git to tell you what it is setting the PATH environment variable to.

$ git config --global alias.whatpath '!echo $PATH'
$ git whatpath
/usr/local/libexec/git-core:/home/user/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Then check each directory listed for the existence of a git-co file. It's not sufficient to do which git-co and assume that if nothing is found that you do not have a git-co file located in one of the directories in Git's PATH; a file may exist that is not executable and which will not display it.

Answer 3

Check to see if you have execute permissions on the git aliases. Providing the execute permissions solved this issue for me.

I downloaded "git-credential-osxkeychain" and added it to /usr/local/bin and provided the exec rights and could run the command without any issue.