https://bugs.gentoo.org/709790
--- a/jpilot-dump.c
+++ b/jpilot-dump.c
@@ -76,7 +76,7 @@ const char *formatT;
  * this code but must be instantiated for the code to compile.  
  * The same is true of the functions which are only used in GUI mode. */
 pid_t jpilot_master_pid = -1;
-int pipe_to_parent;
+extern int pipe_to_parent;
 GtkWidget *glob_dialog;
 GtkWidget *glob_date_label;
 gint glob_date_timer_tag;
--- a/jpilot-sync.c
+++ b/jpilot-sync.c
@@ -37,7 +37,8 @@
 #include "otherconv.h"
 
 /******************************* Global vars **********************************/
-int pipe_to_parent, pipe_from_parent;
+extern int pipe_to_parent;
+int pipe_from_parent;
 pid_t glob_child_pid;
 unsigned char skip_plugins;
 
--- a/jpilot.c
+++ b/jpilot.c
@@ -84,7 +84,8 @@
 /* #define PIPE_DEBUG */
 /******************************* Global vars **********************************/
 /* Application-wide globals */
-int pipe_from_child, pipe_to_parent;
+extern int pipe_to_parent;
+int pipe_from_child;
 int pipe_from_parent, pipe_to_child;
 /* Main GTK window for application */
 GtkWidget *window;