Colin Watson wrote: > Sorry for my long delay in replying to this. No problem; thank you for the response!
> On Mon, Sep 30, 2024 at 02:47:53PM -0700, Josh Triplett wrote: >> I've written a draft patch for this, at >> https://salsa.debian.org/pkg-debconf/debconf/-/merge_requests/18 . I've >> also attached it here. >> >> I'm happy to try other approaches for this, as well; this was the >> simplest. > > I'm trying to understand what's going on with the original setup before > going ahead with this. Your original report shows that the Readline > frontend (based on Teletype) is being used, but > Debconf::FrontEnd::Readline already has a `-t STDIN` check. So your > commit message comments about not having a TTY don't seem quite > accurate: it looks as though the situation is that you _do_ have a TTY > (at least enough for `-t STDIN` to succeed) but that it's broken and > reads from it always return EOF. Does this sound right? (It sounds > quite weird to me, and might point to a bug in your setup.) No, my setup has stdin as /dev/null, and stdout/stderr as UNIX sockets, and no controlling TTY. (And, as you guessed, TERM unset.) Note in particular that it's necessary to have no controlling TTY and have /dev/tty not exist, to avoid debconf's fallbacks that try to find a terminal to use. Apologies for posting a transcript that didn't match the description of the bug I was reporting. The actual issue I was observing was with the teletype frontend, not the readline frontend. (The transcript is from a different, related issue. I expect that 723843 might fix that one.) > It would be helpful for me to have a reproducer for this. If I just try > `env -u TERM apt install tzdata </dev/null`, I get behaviour that, while > somewhat buggy, is not the same as what you reported and doesn't result > in a hang: I'll follow up with the right transcript. > Setting up tzdata (2024b-4) ... > debconf: unable to initialize frontend: Dialog > debconf: (TERM is not set, so the dialog frontend is not usable.) > debconf: falling back to frontend: Readline > debconf: unable to initialize frontend: Readline > debconf: (This frontend requires a controlling tty.) > debconf: falling back to frontend: Teletype > Configuring tzdata > ------------------ > > Please select the geographic area in which you live. Subsequent > configuration > questions will narrow this down by presenting a list of cities, representing > the time zones in which they are located. > > 1. Africa 3. Antarctica 5. Asia 7. Australia 9. Indian > 11. Etc > 2. America 4. Arctic 6. Atlantic 8. Europe 10. Pacific > Geographic area: > Use of uninitialized value $_[1] in join or string at > /usr/share/perl5/Debconf/DbDriver/Stack.pm line 112. > > Current default time zone: '/UTC' > Local time is now: Sun Dec 29 14:35:42 UTC 2024. > Universal Time is now: Sun Dec 29 14:35:42 UTC 2024. > Run 'dpkg-reconfigure tzdata' if you wish to change it. > > Use of uninitialized value $val in substitution (s///) at > /usr/share/perl5/Debconf/Format/822.pm line 84, <GEN6> line 4. > Use of uninitialized value $val in concatenation (.) or string at > /usr/share/perl5/Debconf/Format/822.pm line 85, <GEN6> line 4. > > #723843 is also somewhat related here, although without a reproducer I'm > not quite sure whether it would fix your problem. > > Thanks, > > -- > Colin Watson (he/him) [cjwat...@debian.org]
