diff -urN archive/8.30/man/local.mk src/8.30/man/local.mk
--- archive/8.30/man/local.mk	2018-05-14 06:20:24.000000000 +0200
+++ src/8.30/man/local.mk	2018-08-20 12:04:32.008426334 +0200
@@ -181,6 +181,11 @@
 	     test) prog='['; argv='[';;					\
 		*) prog=$$name; argv=$$prog;;				\
 	esac;								\
+## Double-check whether the built binaries are executable on the build host
+## as the above CROSS_COMPILING condition might have been wrong in some cases.
+	run_help2man="$(run_help2man)";                                 \
+	$(abs_top_builddir)/src/df$(EXEEXT) 2>/dev/null               \
+	|| run_help2man="$(srcdir)/man/dummy-man";                    \
 ## Note the use of $$t/$*, rather than just '$*' as in other packages.
 ## That is necessary to avoid failures for programs that are also shell
 ## built-in functions like echo, false, printf, pwd.