Only for one file, I am getting the following error:
error: unable to write sha1 filename /opt/www/.git/objects/3f/ce3587c54a8be14c69b08c6b01f94949b11b47: Pe
You don't have permission to write in /opt/www/.git/objects/3f.
/opt/www/.git/objects/3f
The quickest solution is to use the sudo command to execute your command with root privileges.
sudo
Solved it for me.