Update SLURM environmental variables used to describe allocation. Retain backwards compatibility to SLURM 1.1 and earlier versions.

This commit was SVN r19647.

orte/mca/ras/slurm/ras_slurm_module.c

@@ -75,11 +75,18 @@ static int orte_ras_slurm_allocate(opal_list_t *nodes)
     }
     regexp = strdup(slurm_node_str);
     
-    tasks_per_node = getenv("SLURM_TASKS_PER_NODE");
+    tasks_per_node = getenv("SLURM_JOB_CPUS_PER_NODE");
     if (NULL == tasks_per_node) {
-        orte_show_help("help-ras-slurm.txt", "slurm-env-var-not-found", 1,
-                       "SLURM_TASKS_PER_NODE");
-        return ORTE_ERR_NOT_FOUND;
+        /* didn't find SLURM 1.2 or above envar - look for prior
+         * version
+         */
+        tasks_per_node = getenv("SLURM_TASKS_PER_NODE");
+        if (NULL == tasks_per_node) {
+            /* couldn't find any version - abort */
+            orte_show_help("help-ras-slurm.txt", "slurm-env-var-not-found", 1,
+                           "SLURM_JOB_CPUS_PER NODE or SLURM_TASKS_PER_NODE");
+            return ORTE_ERR_NOT_FOUND;
+        }
     }
     node_tasks = strdup(tasks_per_node);