Make sure we do not have stale entries inside build-dir/packages

dart/tools/make_links.py

Index: dart/tools/make_links.py
diff --git a/dart/tools/make_links.py b/dart/tools/make_links.py
index 66f94e6b134d2a6b24f0c7ef1eeb51a878ccb025..90092d19314c278e55cb8ace7989ee8d8dd20f3e 100644
--- a/dart/tools/make_links.py
+++ b/dart/tools/make_links.py
@@ -10,6 +10,9 @@ For each SOURCE in SOURCES create a link from SOURCE to TARGET.  If a
 SOURCE ends with .../lib, the lib suffix is ignored when determining
 the name of the target link.
 
+Before creating any links, the old entries of the TARGET directory will be
+removed.
+
 Usage:
   python tools/make_links.py OPTIONS TARGET SOURCES...
 '''
@@ -58,7 +61,13 @@ def create_timestamp_file(options):
 def main(argv):
   (options, args) = get_options()
   target = os.path.relpath(args[0])
-  if not os.path.exists(target):
+  if os.path.exists(target):

[ricow1, 2013/10/23 07:45:44]

why not just simplify to:
if os.path.exists(target):
  shutil.rmtree(target)
os.makedirs(target)

[kustermann, 2013/10/23 07:57:40]

I thought about it as well -- I was just worried that it will follow the "pseudo
links" on windows, but I guess that's not very likely.

Done

+    # If the packages directory already exists, delete the current links inside
+    # it. This is necessary, otherwise we can end up having links in there
+    # pointing to directories which no longer exist (on incremental builds).
+    for link in os.listdir(target):
+      os.remove(os.path.join(target, link))
+  else:
     os.makedirs(target)
   for source in args[1:]:
     # Assume the source directory is named ".../NAME/lib".