diff -Naur freesweep-0.92-orig/configure freesweep-0.92/configure
--- freesweep-0.92-orig/configure	2017-06-03 05:23:58.462903898 -0700
+++ freesweep-0.92/configure	2017-06-03 05:24:40.729953656 -0700
@@ -1,4 +1,4 @@
-#! /bin/sh
+#! /bin/bash
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by Autoconf 2.52.
 #
@@ -97,7 +97,7 @@
 cross_compiling=no
 subdirs=
 MFLAGS= MAKEFLAGS=
-SHELL=${CONFIG_SHELL-/bin/sh}
+SHELL=${CONFIG_SHELL-/bin/bash}
 
 # Maximum number of lines to put in a shell here document.
 # This variable seems obsolete.  It should probably be removed, and