DEVELOPERS.md currently advises Linux users to “ensure that $UID and $GID are set” by placing the following commands in “your .bashrc or other shell configuration”:
export UID=$(id -u) export GID=$(id -g)
But in Bash, $UID is a read-only variable; attempting to set it results in an error:
$ export UID=$(id -u) -bash: UID: readonly variable
Setting $UID may be necessary in some other shells (e. g. dash), but .bashrc is not the right place to configure those.
(None of this applies to $GID, by the way, which is not special in Bash.)