Unfortunately, I cannot reproduce the bug by deliberately running apt update while the captive portal is in effect.
I think I must have hit some obscure edge case that isn't covered by the existing fix. Maybe something to do with switching networks during an automatic update? Who knows. Clearly I haven't got enough information to resolve this. Unfortunately I did not retain a copy of the files I removed, so they cannot be analysed, though I have saved a copy of the current captive portal page if anyone wants me to upload it. (It might differ from the one that triggered the bug for me though.) Apologies for double comment. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to apt in Ubuntu. https://bugs.launchpad.net/bugs/756317 Title: Captive portals may corrupt apt translation indices Status in apt package in Ubuntu: Fix Released Status in apt package in Debian: Fix Released Bug description: I have an adsl modem which returns an html page if the adsl link is broken. This page ends as the content of the apt cache files stored in /var/lib/apt/lists, which breaks apt. The only way to make apt work again is to delete all the files stored in /var/lib/apt/lists. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/756317/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp