Landmines support to ease clobbering builds

DEPS

Index: DEPS
diff --git a/DEPS b/DEPS
index dd7bf5ee67e4f1d67c92457c5506d9f014d2f791..4980a02e0c71dbe4e664ff0eb883c14529e0ff2e 100644
--- a/DEPS
+++ b/DEPS
@@ -48,6 +48,21 @@ include_rules = [
 
 hooks = [
   {
+    # This clobbers when necessary (based on get_landmines.py). It must be the
+    # first hook so that other things that get/generate into the output
+    # directory will not subsequently be clobbered.
+    'name': 'landmines',
+    'pattern': '.',
+    'action': [
+        'python',
+        'src/build/landmines.py',
+        '--landmine-scripts',
+        'src/webrtc/build/get_landmines.py',
+        '--src-dir',
+        'src',

[Michael Achenbach, 2015/10/15 07:38:20]

How is that different to the old default value SRC_DIR in chromium's landmines
script?

Why is only one trybot failing and not all? Did they sync do different chromium
versions?

[kjellander_chromium, 2015/10/15 10:51:41]

I understand your confusion, but since we're using symlinks the actual script
location is chromium/src/build/ so when it tries to lookup the root, it will
become chromium/src and thus put the .landmines file in there, which itself is
probably OK, but I wanted to keep things clean.
It's because we have pools of machines shared between the trybots to optimize
the throughput. Not all machines had performed a build on all their checkouts
yet (which is one of the large disadvantages with that approach).

+    ],
+  },
+  {
     # Check for legacy named top-level dir (named 'trunk').
     'name': 'check_root_dir_name',
     'pattern': '.',