Hi, The copy of gnulib.mk in Emacs says:
# This file is free software, distributed under the terms of the GNU # General Public License. As a special exception to the GNU General # Public License, this file may be distributed as part of a program # that contains a configuration script generated by Autoconf, under # the same distribution terms as the rest of that program. There's no information about which version of the GPL. m4/gl-comp.m4 seems to have the same issue. Also, the licence for the generated lib/Makefile.in and lib/Makefile in Emacs seem confusing/contradictory, perhaps it is related? Makefile.in starts: # Makefile.in generated by automake 1.11.1 from Makefile.am. # @configure_input@ # Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, # 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, # Inc. # This Makefile.in is free software; the Free Software Foundation # gives unlimited permission to copy and/or distribute it, # with or without modifications, as long as this notice is preserved. # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY, to the extent permitted by law; without # even the implied warranty of MERCHANTABILITY or FITNESS FOR A # PARTICULAR PURPOSE. @SET_MAKE@ # Copyright (C) 2002-2011 Free Software Foundation, Inc. # # This file is free software, distributed under the terms of the GNU # General Public License. As a special exception to the GNU General # Public License, this file may be distributed as part of a program # that contains a configuration script generated by Autoconf, under # the same distribution terms as the rest of that program.