root: 91.189.90.11 - - [10/Mar/2011:10:08:32 +0000] "HEAD /%7Evcs-imports/busybox/main/changes HTTP/1.0" 200 - "-" "-"
INF [20110310-10:08:32.545] [47191873160960] loggerhead: Processed ok http://0.0.0.0:8080/%7Evcs-imports/busybox/main/changes [0.440 seconds]
ERR [20110310-10:08:32.546] [47191873160960] root: Traceback (most recent call last):
ERR [20110310-10:08:32.546] [47191873160960] root: File "/srv/codebrowse.launchpad.net/production/launchpad-rev-12559/eggs/Paste-1.7.2-py2.6.egg/paste/httpserver.py", line 1062, in process_request_in_thread
ERR [20110310-10:08:32.546] [47191873160960] root: self.finish_request(request, client_address)
ERR [20110310-10:08:32.546] [47191873160960] root: File "/usr/lib/python2.6/SocketServer.py", line 320, in finish_request
ERR [20110310-10:08:32.546] [47191873160960] root: self.RequestHandlerClass(request, client_address, self)
ERR [20110310-10:08:32.546] [47191873160960] root: File "/usr/lib/python2.6/SocketServer.py", line 615, in __init__
ERR [20110310-10:08:32.546] [47191873160960] root: self.handle()
ERR [20110310-10:08:32.547] [47191873160960] root: File "/srv/codebrowse.launchpad.net/production/launchpad-rev-12559/eggs/Paste-1.7.2-py2.6.egg/paste/httpserver.py", line 436, in handle
ERR [20110310-10:08:32.547] [47191873160960] root: BaseHTTPRequestHandler.handle(self)
ERR [20110310-10:08:32.547] [47191873160960] root: File "/usr/lib/python2.6/BaseHTTPServer.py", line 329, in handle
ERR [20110310-10:08:32.547] [47191873160960] root: self.handle_one_request()
ERR [20110310-10:08:32.547] [47191873160960] root: File "/srv/codebrowse.launchpad.net/production/launchpad-rev-12559/eggs/Paste-1.7.2-py2.6.egg/paste/httpserver.py", line 431, in handle_one_request
ERR [20110310-10:08:32.547] [47191873160960] root: self.wsgi_execute()
ERR [20110310-10:08:32.547] [47191873160960] root: File "/srv/codebrowse.launchpad.net/production/launchpad-rev-12559/eggs/Paste-1.7.2-py2.6.egg/paste/httpserver.py", line 292, in wsgi_execute
ERR [20110310-10:08:32.547] [47191873160960] root: self.wsgi_write_chunk('')
ERR [20110310-10:08:32.547] [47191873160960] root: File "/srv/codebrowse.launchpad.net/production/launchpad-rev-12559/eggs/Paste-1.7.2-py2.6.egg/paste/httpserver.py", line 125, in wsgi_write_chunk
ERR [20110310-10:08:32.547] [47191873160960] root: "Content returned before start_response called")
ERR [20110310-10:08:32.547] [47191873160960] root: RuntimeError: Content returned before start_response called
The first thing that strikes me, is that all of the code is in Paste and Wsgilib, etc. There isn't any Launchpad code here.
My best guess is that we got an exception while processing an exception? Still trying to dig into it.