See http://sourceware.org/ml/crossgcc/2005-12/msg00110.html

Fixes undefined symbol error LIBNSS_FILES_SO when building in glibc/nss
when building on Solaris.

The underlying problem is that generation of a header file is
incorrect because of expected behavior of test -z with an empty string
when using the default /bin/sh on Solaris.

Thanks to Ingo Bremmer for a suggested patch.

===================================================================
--- glibc-2.3.2/Makeconfig	Mon Jun 26 07:09:12 2006
+++ glibc-2.3.2.new/Makeconfig	Mon Jun 26 19:04:12 2006
@@ -773,10 +776,12 @@
 	  else \
 	    $(abi-default_setname) \
 	    lib=`echo $$version | sed 's/=.*$$//'`; \
-	    if eval test -z "\$${versioned_$${lib}}"; then \
-	      eval versioned_$${lib}=yes; \
-	      number=`echo $$version | sed "s/^.*=//"`; \
-	      echo $$lib $$number $${setname:-$${default_setname}}; \
+	    vlib=`eval echo "\$$\{versioned_$${lib}\}"`; \
+	    vlib=`eval echo $${vlib}`; \
+	    if test -z "$$vlib" ; then \
+		eval versioned_$${lib}=yes; \
+		number=`echo $$version | sed "s/^.*=//"`; \
+		echo $$lib $$number $${setname:-$${default_setname}};\
 	    fi; \
 	  fi; \
 	done < $< > $@T; exit 0