Launchpad constructor parameters changed incompatibly in natty

[Martin Pool]

Hydrazine was calling launchpadlib with

        return Launchpad(credentials, service_root, lplib_cachedir)

which syntax was previously, and still is, recommended by <https://help.launchpad.net/API/launchpadlib>.

It turns out a new parameter was inserted near the start in the version in natty, effectively means this succeeds but the service_root parameter is ignored, so your program actually talks to staging.

revno: 102 [merge]
committer: Leonard Richardson <email address hidden>
branch nick: launchpadlib
timestamp: Mon 2010-12-20 15:01:53 -0500
message:
  [r=benji,EdwinGrubbs] If the OAuth token expires in the middle of a launchpadlib session, retrieve another token rather than crashing.
diff:
...

- def __init__(self, credentials, service_root=uris.STAGING_SERVICE_ROOT,
+ def __init__(self, credentials, authorization_engine,
+ service_root=uris.STAGING_SERVICE_ROOT,
                  cache=None, timeout=None, proxy_info=None,
                  version=DEFAULT_VERSION):
         """Root access to the Launchpad API.

         :param credentials: The credentials used to access Launchpad.
         :type credentials: `Credentials`
+ :param authorization_engine: The object used to get end-user input
+ for authorizing OAuth request tokens. Used when an OAuth
+ access token expires or becomes invalid during a
+ session, or is discovered to be invalid once launchpadlib
+ starts up.
+ :type authorization_engine: `RequestTokenAuthorizationEngine`
         :param service_root: The URL to the root of the web service.

If you want a stable Python API, don't change the parameter order.

[Martin Pool (mbp)]

So, on consideration, I don't know if this is going to be worth actually reverting in lplib. Code is already out there; it's getting late to change this in Natty; and hydrazine has a workaround for it. Perhaps it's better to just document it as a break and update the user guide page. And please be more careful in future.

[Max Bowsher (maxb)]

I've written https://help.launchpad.net/API/launchpadlib#launchpadlib%20API%20compatibility documenting this and other failures in compatibility.

[Martin Pool (mbp)]

On 10 April 2011 18:58, Max Bowsher <email address hidden> wrote:
> I've written
> https://help.launchpad.net/API/launchpadlib#launchpadlib%20API%20compatibility
> documenting this and other failures in compatibility.

nice page, shame it exists :}

[Martin Pool (mbp)]

will be fixed in the 0.2 release

[Robert Collins (lifeless)]

Horse has bolted. We would be further incompatible I suspect if we fixed now; so we need to live with it and do better.