run_command: Increase debugging output in case of error

- Thanks to @krinsman in #90.

Author: rkdarst

batchspawner/batchspawner.py

@@ -198,8 +198,11 @@ def run_command(self, cmd, input=None, env=None):
             err = yield proc.wait_for_exit()
         except CalledProcessError:
             self.log.error("Subprocess returned exitcode %s" % proc.returncode)
+            self.log.error('Stdout:')
+            self.log.error(out)
+            self.log.error('Stderr:')
             self.log.error(eout)
-            raise RuntimeError(eout)
+            raise RuntimeError('{} exit status {}: {}'.format(cmd, proc.returncode, eout))
         if err != 0:
             return err # exit error?
         else: