fail if dynvariables cannot be executed successfully

dotdrop/cfg_yaml.py

@@ -209,7 +209,12 @@ class CfgYaml:
 
         # exec dynvariables
         for k in dvar.keys():
-            allvars[k] = shell(allvars[k])
+            ret, out = shell(allvars[k])
+            if not ret:
+                err = 'command \"{}\" failed: {}'.format(allvars[k], out)
+                self.log.error(err)
+                raise YamlException(err)
+            allvars[k] = out
 
         if self.debug:
             self.log.dbg('variables:')

dotdrop/utils.py

@@ -49,8 +49,12 @@ def write_to_tmpfile(content):
 
 
 def shell(cmd):
-    """run a command in the shell (expects a string)"""
-    return subprocess.getoutput(cmd)
+    """
+    run a command in the shell (expects a string)
+    returns True|False, output
+    """
+    ret, out = subprocess.getstatusoutput(cmd)
+    return ret == 0, out
 
 
 def diff(src, dst, raw=True, opts='', debug=False):