add basic bootstrap for coverage

recipes.py

Index: recipes.py
diff --git a/recipes.py b/recipes.py
index 2d59293e4f203d2ac00bbe25b9fcf792c8dddea3..f0173ecf68d9cacc1e90d4dc6e25f361f2f9e441 100755
--- a/recipes.py
+++ b/recipes.py
@@ -218,6 +218,7 @@ def info(args):
 
 
 def main():
+  sysargs = sys.argv

[Paweł Hajdan Jr., 2016/06/15 10:56:19]

What's the intention of this code?

It doesn't seem to copy original contents.

Please either name it e.g. original_sys_argv and make a copy, or remove it and
use sys.argv.

[martiniss, 2016/06/15 20:36:53]

I moved this to where we mutate sys.argv, and made it make a copy.

   from recipe_engine import package
 
   # Super-annoyingly, we need to manually parse for simulation_test since
@@ -249,6 +250,10 @@ def main():
   parser.add_argument('-O', '--project-override', metavar='ID=PATH',
       action=ProjectOverrideAction,
       help='Override a project repository path with a local one.')
+  parser.add_argument(
+      '--use-bootstrap', action='store_true',
+      help='Use bootstrap/bootstrap.py to create a isolated python virtualenv'
+           ' with required python dependencies.')
 
   subp = parser.add_subparsers()
 
@@ -376,6 +381,16 @@ def main():
 
   args = parser.parse_args()
 
+  if args.use_bootstrap:
+    subprocess.check_call(
+        ['bootstrap/bootstrap.py', '--deps-file', 'bootstrap/deps.pyl', 'ENV'],

[Paweł Hajdan Jr., 2016/06/15 10:56:19]

nit: Start with sys.executable .

[martiniss, 2016/06/15 20:36:53]

Done.

+        cwd=os.path.dirname(os.path.realpath(__file__)))
+
+    args = [arg for arg in sysargs[1:] if 'use-bootstrap' not in arg]

[Paweł Hajdan Jr., 2016/06/15 10:56:19]

nit: This might interfere with other legitimate args which might happen to
contain use-bootstrap (e.g. a build property).

Is there some other way we could use to prevent infinite loop here, e.g. an
environment variable similar to how we do for update_scripts, or a
--no-bootstrap flag that overrides any --use-bootstrap flags?

[martiniss, 2016/06/15 20:36:53]

I used an environment variable, like update scripts.

+    return subprocess.call(
+        ['ENV/bin/python', 'recipes.py'] + args,
+        cwd=os.path.dirname(os.path.realpath(__file__)))
+
   if args.verbose:
     logging.getLogger().setLevel(logging.INFO)