Let's say the following is being returned when issuing the git pull command.

error: cannot open .git/FETCH_HEAD: Permission denied

Typically this means you do not have permission to the hidden .git directory (on a Linux system). In this example, user john.doe lacks permission to the hidden .git directory. This can be resolved by either switching to a user that has permission to the hidden .git directory (root in this example) or using the chmod (change mode) command to grant users permission to the hidden .git directory.

[john.doe@localhost ]$ ls -lisa
12582996 0 drwxr-xr-x.  7 root root  101 Oct  8  2020 .
      64 0 drwxr-xr-x. 14 root root  193 Oct  5 22:45 ..
  438286 0 drwxr-xr-x.  8 root root  201 Oct  5 21:53 .git