Execute sinfo with bash shell

conf/uppmax.config

@@ -23,7 +23,7 @@ singularity {
 
 def hostname = "r1"
 try {
-    hostname = "sinfo --local -N -h | grep -m 1 -F -v CLUSTER: | cut -f1 -d' ' ".execute().text.trim()
+    hostname = ['/bin/bash', '-c', 'sinfo --local -N -h | grep -m 1 -F -v CLUSTER: | cut -f1 -d" "'].execute().text.trim()
 } catch (java.io.IOException e) {
     System.err.println("WARNING: Could not run sinfo to determine current cluster, defaulting to rackham")
 }