glibc-2.8 no longer provides the ARG_MAX macro.

--- pdsh-2.14/src/pdsh/xpopen.c
+++ pdsh-2.14/src/pdsh/xpopen.c
@@ -84,10 +84,17 @@
     struct pid *cur;
     int fds[2], read, fd;
     pid_t pid;
-    char *av[ARG_MAX + 1];
     int maxfd = sysconf(_SC_OPEN_MAX);
+    long arg_max;
+    char **av;
+
+    arg_max = sysconf(_SC_ARG_MAX);
+    if (arg_max < 0)
+        errx("%p: unable to get _SC_OPEN_MAX (%m)\n");
+
+    av = Malloc(sizeof(char *) * (arg_max + 1));
     
-    _parse_command_with_quotes(av, ARG_MAX, cmd);
+    _parse_command_with_quotes(av, arg_max, cmd);
 
     if ((*mode != 'r' && *mode != 'w') || mode[1] != '\0') {
         errno = EINVAL;
@@ -101,6 +106,7 @@
     if (pipe(fds) < 0) {
         close(fds[0]);
         close(fds[1]);
+        Free((void **) &av);
         Free((void **) &cur);
         errx("%p: unable to dup stdout\n");
     }
@@ -143,6 +149,8 @@
     cur->next = pidlist;
     pidlist = cur;
 
+    Free((void **) &av);
+
     return (cur->fp);
 
 }