UploadUnhappinessError reported with a backtrace

[np]

The tahoe CLI interface should display nicer error messages than backtraces.

[np]

Traceback (most recent call last):
  File "/home/ertai/w/a/tahoe/support/bin/tahoe", line 8, in <module>
    load_entry_point('allmydata-tahoe==1.6.1-r4442', 'console_scripts', 'tahoe')()
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/runner.py", line 102, in run
    rc = runner(sys.argv[1:])
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/runner.py", line 89, in runner
    rc = cli.dispatch[command](so)
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/cli.py", line 510, in backup
    rc = tahoe_backup.backup(options)
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/tahoe_backup.py", line 319, in backup
    return bu.run()
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/tahoe_backup.py", line 116, in run
    new_backup_dircap = self.process(options.from_dir)
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/tahoe_backup.py", line 205, in process
    newdircap = mkdir(create_contents, self.options)
  File "/home/ertai/w/a/tahoe/src/allmydata/scripts/tahoe_backup.py", line 45, in mkdir
    raise HTTPError("Error during mkdir", resp)
allmydata.scripts.common_http.HTTPError: Error during mkdir: 500 Internal Server Error
Traceback (most recent call last):
  File "/home/ertai/w/a/tahoe/support/lib/python2.6/site-packages/foolscap-0.5.1-py2.6.egg/foolscap/call.py", line 674, in _done
    self.request.complete(res)
  File "/home/ertai/w/a/tahoe/support/lib/python2.6/site-packages/foolscap-0.5.1-py2.6.egg/foolscap/call.py", line 60, in complete
    self.deferred.callback(res)
  File "/usr/lib/python2.6/site-packages/twisted/internet/defer.py", line 280, in callback
    self._startRunCallbacks(result)
  File "/usr/lib/python2.6/site-packages/twisted/internet/defer.py", line 354, in _startRunCallbacks
    self._runCallbacks()
--- <exception caught here> ---
  File "/usr/lib/python2.6/site-packages/twisted/internet/defer.py", line 371, in _runCallbacks
    self.result = callback(self.result, *args, **kw)
  File "/home/ertai/w/a/tahoe/src/allmydata/immutable/upload.py", line 506, in _got_response
    return self._loop()
  File "/home/ertai/w/a/tahoe/src/allmydata/immutable/upload.py", line 420, in _loop
    raise UploadUnhappinessError(msg)
allmydata.interfaces.UploadUnhappinessError: peer selection failed for <Tahoe2PeerSelector for upload qaym4>: shares could be placed or found on only 2 server(s). We were asked to place shares on at least 7 server(s) such that any 3 of them have enough shares to recover the file. (placed 5 shares out of 10 total (5 homeless), want to place shares on at least 7 servers such that any 3 of them have enough shares to recover the file, sent 7 queries to 5 peers, 4 queries placed some shares, 3 placed none (of which 3 placed none due to the server being full and 0 placed none due to an error))

[davidsarah]

Duplicate of #1048 and/or #1047.