Source grub-mkconfig_lib from the build directory at build time.

util/powerpc/ieee1275/grub-mkrescue.in

@@ -32,12 +32,15 @@ platform=@platform@
 pkglibdir=${libdir}/`echo ${PACKAGE_TARNAME}/${target_cpu}-${platform} | sed ${transform}`
 datarootdir="@datarootdir@"
 datadir="@datadir@"
+if [ "x$pkgdatadir" = x ]; then
+    pkgdatadir="${datadir}/`echo @PACKAGE_TARNAME@ | sed "${transform}"`"
+fi
 
 self=`basename $0`
 
 grub_mkimage="${bindir}/`echo grub-mkimage | sed ${transform}`"
 
-. "${datadir}/@PACKAGE@/grub-mkconfig_lib"
+. "${pkgdatadir}/grub-mkconfig_lib"
 
 # Usage: usage
 # Print the usage.