Do not for call cvmfsexec script if not necessary. Fixes #308

creation/lib/cgWParamDict.py

@@ -326,8 +326,9 @@ def populate(self, other=None):
  # framing the arguments to the subprocess wrapper as a string
  # executing the cvmfsexec distribution building script can be done without explicitly specifying the location of the script since it is in the PATH variable (directory is /usr/bin/ which is set as the standard for the RPM installation)
  args = " ".join(["create_cvmfsexec_distros.sh", "--work-dir", self.work_dir, cfgs, mtypes])
- cvmfsexec_distros_build_out = subprocessSupport.iexe_cmd(args)
- print(cvmfsexec_distros_build_out) # prints the output from the shell script executed in the previous line
+ if cfgs != "" and mtypes != "":
+ cvmfsexec_distros_build_out = subprocessSupport.iexe_cmd(args)
+ print(cvmfsexec_distros_build_out) # prints the output from the shell script executed in the previous line
  if cfgs: # since 'sources' is a required attribute and therefore used as a control knob
  # get the location of the tarballs created during reconfig/upgrade
  distros_loc = os.path.join(self.work_dir, "cvmfsexec/tarballs")