Make sure $host and $host_os are defined when used. * m4/argz.m4 (gl_FUNC_ARGZ): Require AC_CANONICAL_HOST. * m4/closedir.m4 (gl_FUNC_CLOSEDIR): Likewise. * m4/csharpexec.m4 (gt_CSHARPEXEC): Likewise. * m4/dirfd.m4 (gl_FUNC_DIRFD): Likewise. * m4/expl.m4 (gl_FUNC_EXPL): Likewise. * m4/ls-mntd-fs.m4 (gl_LIST_MOUNTED_FILE_SYSTEMS): Likewise. * m4/lstat.m4 (gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK): Likewise. * m4/opendir.m4 (gl_FUNC_OPENDIR): Likewise. * m4/poll.m4 (gl_FUNC_POLL): Likewise. * m4/pselect.m4 (gl_FUNC_PSELECT): Likewise. * m4/ptsname.m4 (gl_FUNC_PTSNAME): Likewise. * m4/relocatable.m4 (gl_RELOCATABLE_BODY): Likewise. * m4/symlinkat.m4 (gl_FUNC_SYMLINKAT): Likewise. * m4/ceill.m4 (gl_FUNC_CEILL): Require AC_CANONICAL_HOST outside the m4_ifdef block.

--- a/m4/relocatable.m4	Mon Jul 10 02:20:20 2017 +0200
+++ b/m4/relocatable.m4	Mon Jul 10 12:35:06 2017 +0200
@@ -1,4 +1,4 @@
-# relocatable.m4 serial 18
+# relocatable.m4 serial 19
 dnl Copyright (C) 2003, 2005-2007, 2009-2017 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -31,6 +31,7 @@
   AC_BEFORE([AC_PROG_INSTALL],[gl_RELOCATABLE_BODY])
   AC_REQUIRE([AC_LIB_LIBPATH])
   AC_REQUIRE([gl_RELOCATABLE_LIBRARY_BODY])
+  AC_REQUIRE([AC_CANONICAL_HOST])
   is_noop=no
   use_elf_origin_trick=no
   use_wrapper=no