From 4422c4c0a2d1b5ffa52c771bc094385782fdb151 Mon Sep 17 00:00:00 2001
From: Sam Thursfield <sam.thursfield@codethink.co.uk>
Date: Wed, 15 Apr 2015 17:13:13 +0000
Subject: distbuild: Don't create a directory for build output until we get
 some

Currently, it leaves around empty directories called build-00, build-01,
etc. when you run a distbuild that fails to get as far as building
something, which is annoying.

Change-Id: Id3466e248c327dedaf973bc2fe22d42e5c5570d4
---
 distbuild/initiator.py | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/distbuild/initiator.py b/distbuild/initiator.py
index 48299a3d..35d10147 100644
--- a/distbuild/initiator.py
+++ b/distbuild/initiator.py
@@ -70,10 +70,10 @@ class Initiator(distbuild.StateMachine):
         self._step_outputs = {}
         self.debug_transitions = False
 
-        if app.settings['initiator-step-output-dir'] == '':
-            self._step_output_dir = create_build_directory()
-        else:
-            self._step_output_dir = app.settings['initiator-step-output-dir']
+        # The build-log output dir is set up in _open_output() when we
+        # receive the first log message. Thus if we never get that far, we
+        # don't leave an empty build-00/ directory lying around.
+        self._step_output_dir = None
 
     def setup(self):
         distbuild.crash_point()
@@ -140,13 +140,21 @@ class Initiator(distbuild.StateMachine):
     def _handle_build_progress_message(self, msg):
         self._app.status(msg='Progress: %(msgtext)s', msgtext=msg['message'])
 
+    def _get_step_output_dir(self):
+        if self._step_output_dir is None:
+            configured_dir = self._app.settings['initiator-step-output-dir']
+            if configured_dir == '':
+                self._step_output_dir = create_build_directory()
+            else:
+                self._step_output_dir = configured_dir
+        return self._step_output_dir
+
     def _open_output(self, msg):
         assert msg['step_name'] not in self._step_outputs
-        if self._step_output_dir:
-            filename = os.path.join(self._step_output_dir,
-                                    'build-step-%s.log' % msg['step_name'])
-        else:
-            filename = '/dev/null'
+
+        path = self._get_step_output_dir()
+        filename = os.path.join(path,
+                               'build-step-%s.log' % msg['step_name'])
         f = open(filename, 'a')
         self._step_outputs[msg['step_name']] = f
 
-- 
cgit v1.2.1