configure: Add a --disable-rpath option to prevent libtool hardcoding rpath variables.

CHANGELOG.md

@@ -9,6 +9,7 @@ The espeak-ng project is a fork of the espeak project.
 
 ### 1.49.3 - (In Development)
 
+*  Add a `--disable-rpath` option to prevent libtool hardcoding rpaths in the executable.
 *  Add more tests to check the various parts of espeak-ng.
 *  Various changes to clean up the codebase.
 *  Fix various compiler warnings (`-Winitialized`, `-Wmissing-prototypes`, `-Wreturn-type`,

configure.ac

@@ -14,6 +14,11 @@ dnl ================================================================
 dnl configure arguments
 dnl ================================================================
 
+AC_ARG_ENABLE([rpath],
+    [AS_HELP_STRING([--enable-rpath], [set hardcoded rpaths in the executable @<:@default=yes@:>@])],
+    [],
+    [enable_rpath=yes])
+
 AC_ARG_WITH([gradle],
     [AS_HELP_STRING([--with-gradle], [specify the gradle program to use @<:@default=gradle@:>@])],
     [GRADLE=$with_gradle],
@@ -310,6 +315,14 @@ dnl ================================================================
 AC_CONFIG_FILES([Makefile espeak-ng.pc])
 AC_OUTPUT
 
+if test "$enable_rpath" = "yes" ; then
+	true
+else
+	# See https://old-en.opensuse.org/openSUSE:Packaging_Guidelines#Removing_Rpath
+	sed -i 's|^hardcode_libdir_flag_spec=.*|hardcode_libdir_flag_spec=""|g' libtool
+	sed -i 's|^runpath_var=LD_RUN_PATH|runpath_var=DIE_RPATH_DIE|g' libtool
+fi
+
 AC_MSG_NOTICE([
 
     Configuration for eSpeak NG complete.