--- sbsigntools/configure.ac	2018-09-25 10:30:00.878766256 -0500
+++ configure.ac.new	2018-09-25 10:34:56.231277375 -0500
@@ -71,15 +71,16 @@
 # no consistent view of where gnu-efi should dump the efi stuff, so find it
 ##
 for path in /lib /lib64 /usr/lib /usr/lib64 /usr/lib32 /lib/efi /lib64/efi /usr/lib/efi /usr/lib64/efi; do
-    if test -e $path/crt0-efi-$EFI_ARCH.o; then
-       CRTPATH=$path
+    if test -e @@NIX_GNUEFI@@/$path/crt0-efi-$EFI_ARCH.o; then
+       CRTPATH=@@NIX_GNUEFI@@/$path
+       break
     fi
 done
 if test -z "$CRTPATH"; then
    AC_MSG_ERROR([cannot find the gnu-efi crt path])
 fi
 
-EFI_CPPFLAGS="-I/usr/include/efi -I/usr/include/efi/$EFI_ARCH \
+EFI_CPPFLAGS="-I@@NIX_GNUEFI@@/include/efi -I@@NIX_GNUEFI@@/include/efi/$EFI_ARCH \
  -DEFI_FUNCTION_WRAPPER"
 CPPFLAGS_save="$CPPFLAGS"
 CPPFLAGS="$CPPFLAGS $EFI_CPPFLAGS"
@@ -90,5 +91,5 @@
 AC_SUBST(CRTPATH, $CRTPATH)
 
 AC_CONFIG_FILES([Makefile src/Makefile lib/ccan/Makefile]
-		[docs/Makefile tests/Makefile])
+		[docs/Makefile])
 AC_OUTPUT