Without this patch gdiff3 and gsdiff don't
find diff - program that both of them call.

--- diffutils-3.8/src/Makefile.in	2021-08-02 03:20:12.000000000 +0000
+++ diffutils-3.8/src/Makefile.in	2021-08-03 15:06:02.264532452 +0000
@@ -1613,7 +1613,7 @@ noinst_HEADERS = \
   system.h
 
 MOSTLYCLEANFILES = paths.h paths.ht
-gdiff = `echo diff|sed '$(transform)'`
+gdiff = /usr/gnu/bin/diff
 BUILT_SOURCES = paths.h version.c version.h
 noinst_LIBRARIES = libver.a
 nodist_libver_a_SOURCES = version.c version.h