bitbake: bb.parse: properly error out on filesystem errors

We've had a long-standing bug where a legitimate error reading a file (IOError
or OSError) is always suppressed as though it was a 'file not found' case. As
a concrete example, if you do a `chmod 000 conf/local.conf`, it'll silently
not parse local.conf, rather than erroring to let the user know about the
problem.

Fix this by handling the ENOENT case specifically.

(Bitbake rev: e691312a3add222b04e7b2f52f8df6abcb9068bf)

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/parse/__init__.py

@@ -26,9 +26,10 @@ File parsers for the BitBake build tools.
 
 handlers = []
 
+import errno
+import logging
 import os
 import stat
-import logging
 import bb
 import bb.utils
 import bb.siggen
@@ -122,12 +123,12 @@ def resolve_file(fn, d):
         for af in attempts:
             mark_dependency(d, af)
         if not newfn:
-            raise IOError("file %s not found in %s" % (fn, bbpath))
+            raise IOError(errno.ENOENT, "file %s not found in %s" % (fn, bbpath))
         fn = newfn
 
     mark_dependency(d, fn)
     if not os.path.isfile(fn):
-        raise IOError("file %s not found" % fn)
+        raise IOError(errno.ENOENT, "file %s not found" % fn)
 
     return fn