[Debconf-devel] Bug#929417: debconf: Readline frontend should check that stdin is a tty (to fix Docker build freezes)

[Tianon Gravi]

On Thu, Apr 16, 2020 at 04:56:58PM -0700, Tianon Gravi wrote:
> As a bit of added versioning information, this affects Debian Stretch
> (1.5.61) and newer, but Debian Jessie (1.5.56+deb8u1) is unaffected
> (and over in Ubuntu land, Xenial is unaffected at 1.5.58ubuntu2, but
> Bionic at 1.5.66ubuntu1 and newer *is* affected).

Actually, scratch that -- Jessie is also affected.  I was testing with
"tzdata" and it worked in Jessie, but testing with the example Anders
provided of "keyboard-configuration" I was able to reproduce even on
Jessie.

Going back to Squeeze, I was no longer able to reproduce:

| ...
| Setting up keyboard-configuration (1.68+squeeze2) ...
| 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 keyboard-configuration
| ----------------------------------
| 
| Please select the layout matching the keyboard for this machine.
| 
|   1. USA
|   2. USA - Alternative international (former us_intl)
|   3. USA - Cherokee
|   4. USA - Classic Dvorak
|   5. USA - Colemak
|   6. USA - Dvorak
|   7. USA - Dvorak international
|   8. USA - Group toggle on multiply/divide key
|   9. USA - International (AltGr dead keys)
|   10. USA - International (with dead keys)
|   11. USA - Left handed Dvorak
|   12. USA - Macintosh
|   13. USA - Programmer Dvorak
|   14. USA - Right handed Dvorak
|   15. USA - Russian phonetic
|   16. USA - With EuroSign on 5
|   17. Other
| 
| Keyboard layout: 
| Use of uninitialized value $_[1] in join or string at /usr/share/perl5/Debconf/DbDriver/Stack.pm line 111.
| Use of uninitialized value $val in substitution (s///) at /usr/share/perl5/Debconf/Format/822.pm line 83, <GEN6> line 5.
| Use of uninitialized value $val in concatenation (.) or string at /usr/share/perl5/Debconf/Format/822.pm line 84, <GEN6> line 5.
| Setting up libgdbm3 (1.8.3-9) ...
| ...

♥,
- Tianon
  4096R / B42F 6819 007F 00F8 8E36  4FD4 036A 9C25 BF35 7DD4