Configure erroneously says uucp group does not exist

In a message to the mailing list Rainer Woitok mentioned the following:

[...] For a first test I checked out changeset 1942c5fd. However while running

   ./autogen.sh && ./configure

I got two warnings which I do not quite understand:

   configure: WARNING: Group uucp does not exist on this system.
   configure: WARNING: Locking feature will be disabled.

The group does in fact exist:

   $ ls -l /etc/group /etc/gshadow
   -rw-r--r-- 1 root root 755 2020-01-14 10:03 /etc/group
   -r--r----- 1 root root 622 2020-01-14 10:03 /etc/gshadow
   $ grep uucp /etc/group /etc/gshadow
   /etc/group:uucp:x:14:uucp
   /etc/gshadow:uucp:::uucp
   $

The same warning is only issued on our fedora-31-clang builds. There the uucp group is not in /etc/group and /etc/gshadow has 0000 permissions.
On our debian-10-full build the uucp group exists and has no members other than uucp.