In gettext-tools, both `libgrep` and `gnulib-lib` provide their own versions of
headers like `stdlib.h`, but the two variants aren't the same. Some of the tools
want to use `unsetenv()` as provided by gnulib-lib, but the default include flag
ordering puts libgrep first, which doesn't define it. This is all pretty messy
but the most expedient thing is to reorder the includes to get the gnulib-lib
version first.

diff --git a/gettext-tools/src/Makefile.am b/gettext-tools/src/Makefile.am
index 607dcf0..c641919 100644
--- a/gettext-tools/src/Makefile.am
+++ b/gettext-tools/src/Makefile.am
@@ -109,8 +109,8 @@ schemadir = $(pkgdatadir)/schema
 # The option -I$(top_srcdir) is needed so that woe32dll/export.h is found.
 AM_CPPFLAGS = \
   -I$(top_srcdir) \
-  -I../libgrep -I$(top_srcdir)/libgrep \
   -I../gnulib-lib -I$(top_srcdir)/gnulib-lib \
+  -I../libgrep -I$(top_srcdir)/libgrep \
   -I../../gettext-runtime/intl -I$(top_srcdir)/../gettext-runtime/intl
 DEFS = \
   -DLOCALEDIR=$(localedir_c_make) \