Rather than crashing, simply display a message when pcigale.ini is missing.

CHANGELOG.md

@@ -8,6 +8,8 @@
 - We do not output the break strength from the `bc03` module anymore as these were not computed properly. (Médéric Boquien)
 
 ### Fixed
+- When the pcigale.ini file was missing, pcigale would crash and display a fairly cryptic backtrace. Now it explicitly states that the file could not be found. (Médéric Boquien)
+
 ### Optimised
 
 ## 0.10.0 (2016-09-15)

pcigale/session/configuration.py

@@ -6,6 +6,8 @@
 import pkgutil
 from collections import Iterable, OrderedDict
 import multiprocessing as mp
+import os.path
+import sys
 from textwrap import wrap
 
 import configobj
@@ -57,6 +59,8 @@ class Configuration(object):
         # we actually return the configuration file from the property() method.
         self.config.validate(validate.Validator(validation.functions))
 
+        self.pcigaleini_exists = os.path.isfile(filename)
+
     def create_blank_conf(self):
         """Create the initial configuration file
 
@@ -127,6 +131,9 @@ class Configuration(object):
         selection based on the filters identified in the data table file.
 
         """
+        if self.pcigaleini_exists is False:
+            print("Error: pcigale.ini could not be found.")
+            sys.exit(1)
 
         # Getting the list of the filters available in pcigale database
         with Database() as base:
@@ -220,6 +227,10 @@ class Configuration(object):
         configuration: dictionary
             Dictionary containing the information provided in pcigale.ini.
         """
+        if self.pcigaleini_exists is False:
+            print("Error: pcigale.ini could not be found.")
+            sys.exit(1)
+
         self.complete_redshifts()
         self.complete_analysed_parameters()