Cygwin startup error /usr/bin/id: cannot find name for group ID

Solution 1:

It appears to be related to my Active Directory username or group memberships. The error went away after running the following command as per this article:

mkpasswd -l -c > /etc/passwd; mkgroup -l -d > /etc/group

This updates the cygwin files with the latest AD user/group information.

Solution 2:

None of the modifications of /etc/group nor /etc/passwd helped me (not even those from the cited article). The problem was that I was trying to install babun under Domain User but without connection to the Domain network. After connecting to the Domain network everything worked fine out of the box.

Solution 3:

Instead of

mkgroup -l -d > /etc/group

I fixed the groups by issuing the two commands

mkgroup -l > /etc/group
mkgroup -c >> /etc/group

suggested further down in the comments of the article Cygwin users and groups.