Upstream-status: Taken from Debian upstream:
    <https://salsa.debian.org/hurd-team/gnumach/-/raw/master/debian/patches/12_version_suffix.patch>

Index: gnumach/configure.ac
===================================================================
--- gnumach.orig/configure.ac
+++ gnumach/configure.ac
@@ -19,6 +19,7 @@ AC_PREREQ([2.57])
 m4_include([version.m4])
 AC_INIT([AC_PACKAGE_NAME], [AC_PACKAGE_VERSION], [AC_PACKAGE_BUGREPORT],
   [AC_PACKAGE_TARNAME])
+AC_SUBST([PACKAGE_VERSION_SUFFIX])
 AC_CONFIG_SRCDIR([kern/ipc_kobject.c])
 
 if test -z "${CFLAGS+set}"; then
Index: gnumach/version.c.in
===================================================================
--- gnumach.orig/version.c.in
+++ gnumach/version.c.in
@@ -1,2 +1,2 @@
 /* @configure_input@ */
-const char version[] = "@PACKAGE_NAME@ @PACKAGE_VERSION@";
+const char version[] = "@PACKAGE_NAME@ @PACKAGE_VERSION@@PACKAGE_VERSION_SUFFIX@";