Background

1. I created a bare Git repository in my USB stick on GUI.
2. I pushed some Git commits to the bare repository in the USB.

The commands for the above steps shouldn’t be difficult. In step 2, if one sets the upstream repository to the bare repository in the USB, the command to be issued is even easier: just git push will do, and the remote and branch names can be omitted.

Problem

I worked on Linux text mode instead of GUI. After committing the changes, I tried pushing them into the bare Git repository in the USB.

[owner@localhost ~/MATH2220]$ git status
On branch master
Your branch is ahead of 'origin/master' by 1 commit.
  (use "git push" to publish your local commits)
nothing to commit, working directory clean
[owner@localhost ~/MATH2220]$ sudo mount -t vfat /dev/sdf1 \
> /media/owner/08F1-B181/
[owner@localhost ~/MATH2220]$ git push
Counting objects: 4, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (4/4), 551 bytes | 0 bytes/s, done.
Total 4 (delta 1), reused 0 (delta 0)
remote: error: insufficient permission for adding an object to repository databa
se objects
remote: fatal: failed to write object
error: unpack failed: unpack-objects abnormal exit
To /media/owner/08F1-B181/MATH2220/MATH2220.git
 ! [remote rejected] master -> master (unpacker error)
error: failed to push some refs to '/media/owner/08F1-B181/MATH2220/MATH2220.git
'

How can I push commits into the USB?

Solution

I googled “git push usb rejected” for a similar problem, and “linux text mode git” for a Git tutorial on CLI, but I couldn’t find what I wanted. I observed that this wasn’t a problem of Git, but a problem about file permissions on *nix.

[owner@localhost ~/MATH2220]$ ll /media/owner/
total 12
drwxr-x---+ 3 root root 4096 Jan  1 21:40 ./
drwxr-xr-x  4 root root 4096 Aug 13 02:09 ../
drwxr-xr-x  2 root root 4096 Jan  1 21:40 08F1-B181/

Then I changed the search words, and finally found a page on SUSE Communities.¹ I read the commands and their descriptions, and eventually solved the problem.

After I had unmounted the USB drive, I typed the command for mounting the USB stick again.

[owner@localhost ~/MATH2220]$ sudo umount /media/owner/08F1-B181/
[owner@localhost ~/MATH2220]$ sudo mount -t vfat -o uid=owner,gid=owner\
> /dev/sdf1 /media/owner/08F1-B181/
[owner@localhost ~/MATH2220]$ git push
Counting objects: 4, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (4/4), 551 bytes | 0 bytes/s, done.
Total 4 (delta 1), reused 0 (delta 0)
To /media/owner/08F1-B181/MATH2220/MATH2220.git
   9e8e53e..4fa36c7  master -> master

Lessons learnt

One can specify the owner and the user group of the VFAT filesystem to be mounted with -o uid=foo,gid=bar for USB devices.

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