Public bug reported: I attempted to perform a release update today from maverick to natty. Both update-manager -c and do-release-update indicated that no newer releases were available.
After some investigation, I discovered the following was the culprit: david@marshall:~$ export DEBUG_UPDATE_MANAGER=1 david@marshall:~$ do-release-upgrade Checking for a new ubuntu release MetaRelease.__init__() useDevel=False useProposed=False /etc/update-manager/meta-release: http://changelogs.ubuntu.com/meta-release /etc/update-manager/meta-release: http://changelogs.ubuntu.com/meta-release-lts /etc/update-manager/meta-release: -development /etc/update-manager/meta-release: -proposed metarelease-uri: http://changelogs.ubuntu.com/meta-release MetaRelease.download() result of meta-release download: 'HTTP Error 304: Not Modified' reading file '/home/david/.cache/update-manager-core/meta-release' have self.metarelease_information MetaRelease.parse() current dist name: 'maverick' current dist not found in meta-release file No new release found david@marshall:~$ ls -l ~/.cache/update-manager-core/meta-release -rw-r--r-- 1 david david 780 2011-06-30 18:14 /home/david/.cache/update-manager-core/meta-release david@marshall:~$ cat ~/.cache/update-manager-core/meta-release <html> <!-- <?xml version="1.0" encoding="UTF-8"?> <WISPAccessGatewayParam xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xsi:noNamespaceSchemaLocation="http://192.168.10.1/xml/WISPAccessGatewayParam.xsd";> <Redirect> <AccessProcedure>1.0</AccessProcedure> <AccessLocation></AccessLocation> <LocationName></LocationName> <LoginURL>http://192.168.10.1/login?target=xml</LoginURL> <MessageType>100</MessageType> <ResponseCode>0</ResponseCode> </Redirect> </WISPAccessGatewayParam> --> <head> <title>...</title> <meta http-equiv="refresh" content="0; url=http://192.168.10.1/login?dst=http%3A%2F%2Fchangelogs.ubuntu.com%2Fmeta-release";> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="expires" content="-1"> </head> <body> </body> </html> --------------- As you can likely tell, I was behind a captive portal on 2011-06-30. Update manager [automatically] attempted to retrieve the meta-release file at that time, and--even though it likely had a valid file before--grabbed the captive portal page, because it was newer. Now when update-manager-core calls self.download(), the following is added: req.add_header("If-Modified-Since", time.asctime(time.gmtime(lastmodified))) The meta-release file on the changelog.ubuntu.com server hasn't been changed since I used the captive portal (and likely only changes when a new release cycle begins), so the server returns HTTP 304 (not modified), and the client relies on the cached copy on disk (which is bogus). Neither MetaReleaseCore::download() nor MetaReleaseCore::parse() really care that the file on disk is obviously not the right format, with ::parse() simply returning false to nothing (unchecked return value in ::download()). Given the small size of meta-release (6.7k), it hardly seems worth the effort of adding complexity necessary to avoid potentially re- downloading this data occasionally, but I suppose it's your prerogative. One workaround while still achieving this goal might be to check the server date is newer *OR* filesize does not match with a HEAD request prior to GET (and without If-Modified-Since), though this still leaves the window open for the corner case of a captive portal page exactly the same size as the meta-release file. Additionally, if ::parse() returns false, it may be worthwhile to delete the .cache version of the meta-release file (and try to download it one more time?) (and tell the user something more useful than "no update available"?). ProblemType: Bug DistroRelease: Ubuntu 10.10 Package: update-manager-core 1:0.142.23 ProcVersionSignature: Ubuntu 2.6.35-30.54-generic 2.6.35.13 Uname: Linux 2.6.35-30-generic x86_64 NonfreeKernelModules: nvidia Architecture: amd64 Date: Thu Jul 7 16:40:27 2011 InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429) ProcEnviron: LC_TIME=en_DK.utf8 PATH=(custom, user) LANG=en_US.utf8 SHELL=/bin/bash SourcePackage: update-manager ** Affects: update-manager-core (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug maverick -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/807259 Title: MetaRelease.download() Issue after Captive Portal To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/update-manager-core/+bug/807259/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
