I upgraded the phabricator machine to ubuntu 15.10. I did *not* upgrade phabricator or change its database. All attempts to authenticate with google authentication now fail with the attached log. (I can login to google ok, but then it fails inside phabricator somewhere). Existing logins are ok, this only happens if you logout and attempt to reauthenticate.
Ubuntu 15.10 is using php 5.6.11, previously ubuntu 15.04 was using php 5.6.4.
I'll keep investigating, but if you have any ideas, I'd appreciate it!
```
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: [2016-01-26 11:55:37] EXCEPTION: (HTTPFutureHTTPResponseStatus) [HTTP/400]
{
"error" : "invalid_grant",
"error_description" : "Code was already redeemed."
} at [<phutil>/src/future/http/BaseHTTPFuture.php:339]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: arcanist(head=master, ref.master=a03c6079bb71), phabricator(head=master, ref.master=d92f7a14739a), phutil(head=master, ref.master=59f5a8d2bb82), sprint(head=master, ref.master=3fbeaf53a042)
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #0 <#2> BaseHTTPFuture::parseRawHTTPResponse(string) called at [<phutil>/src/future/http/HTTPSFuture.php:415]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #1 <#2> HTTPSFuture::isReady() called at [<phutil>/src/future/Future.php:37]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #2 <#2> Future::resolve() called at [<phutil>/src/future/http/BaseHTTPFuture.php:279]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #3 <#2> BaseHTTPFuture::resolvex() called at [<phutil>/src/auth/PhutilOAuthAuthAdapter.php:174]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #4 <#2> PhutilOAuthAuthAdapter::makeTokenRequest(array) called at [<phutil>/src/auth/PhutilOAuthAuthAdapter.php:161]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #5 <#2> PhutilOAuthAuthAdapter::loadAccessTokenData() called at [<phutil>/src/auth/PhutilOAuthAuthAdapter.php:122]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #6 <#2> PhutilOAuthAuthAdapter::getAccessTokenData(string) called at [<phutil>/src/auth/PhutilOAuthAuthAdapter.php:109]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #7 <#2> PhutilOAuthAuthAdapter::getAccessToken() called at [<phutil>/src/auth/PhutilGoogleAuthAdapter.php:98]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #8 <#2> PhutilGoogleAuthAdapter::loadOAuthAccountData() called at [<phutil>/src/auth/PhutilOAuthAuthAdapter.php:223]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #9 <#2> PhutilOAuthAuthAdapter::getOAuthAccountData(string, array) called at [<phutil>/src/auth/PhutilGoogleAuthAdapter.php:17]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #10 <#2> PhutilGoogleAuthAdapter::getAccountID() called at [<phabricator>/src/applications/auth/provider/PhabricatorOAuth2AuthProvider.php:83]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #11 <#2> PhabricatorOAuth2AuthProvider::processLoginRequest(PhabricatorAuthLoginController) called at [<phabricator>/src/applications/auth/controller/PhabricatorAuthLoginController.php:40]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #12 <#2> PhabricatorAuthLoginController::handleRequest(AphrontRequest) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:237]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #13 phlog(HTTPFutureHTTPResponseStatus) called at [<phabricator>/src/aphront/handler/PhabricatorDefaultRequestExceptionHandler.php:32]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #14 PhabricatorDefaultRequestExceptionHandler::handleRequestException(AphrontRequest, HTTPFutureHTTPResponseStatus) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:632]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #15 AphrontApplicationConfiguration::handleException(HTTPFutureHTTPResponseStatus) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:242]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #16 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phabricator>/src/aphront/configuration/AphrontApplicationConfiguration.php:149]
Jan 26 11:55:37 phabricator php5-fpm[1491]: ool www[1491]: #17 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phabricator>/webroot/index.php:17]
```