Since there is no progress on this bug and maintenance of this package appears to be slow overall, I propose the following NMU patch.
diff -u gpm-1.20.4/debian/changelog gpm-1.20.4/debian/changelog --- gpm-1.20.4/debian/changelog +++ gpm-1.20.4/debian/changelog @@ -1,3 +1,10 @@ +gpm (1.20.4-3.2) UNRELEASED; urgency=low + + * Non-maintainer upload. + * debian/patches/070_struct_ucred: fix FTBFS. Closes: #520853 + + -- Peter Eisentraut <pet...@debian.org> Thu, 23 Apr 2009 22:04:24 +0300 + gpm (1.20.4-3.1) unstable; urgency=low [ Thomas Viehmann ] diff -u gpm-1.20.4/debian/patches/series gpm-1.20.4/debian/patches/series --- gpm-1.20.4/debian/patches/series +++ gpm-1.20.4/debian/patches/series @@ -17,0 +18 @@ +070_struct_ucred only in patch2: unchanged: --- gpm-1.20.4.orig/debian/patches/070_struct_ucred +++ gpm-1.20.4/debian/patches/070_struct_ucred @@ -0,0 +1,14 @@ +bug #520853 + +Index: gpm-1.20.4/src/daemon/processconn.c +=================================================================== +--- gpm-1.20.4.orig/src/daemon/processconn.c 2009-03-20 17:35:10.000000000 +0000 ++++ gpm-1.20.4/src/daemon/processconn.c 2009-03-20 17:42:44.000000000 +0000 +@@ -19,6 +19,7 @@ + * + ********/ + ++#define _GNU_SOURCE /* needed for struct ucred */ + #include <sys/socket.h> /* accept */ + #include <stdlib.h> /* malloc */ + #include <unistd.h> /* close */