Package: debconf Version: 1.5.84 Severity: normal X-Debbugs-Cc: j...@joshtriplett.org
I'm building a system for remotely running noninteractive commands. That system lets people run commands like `apt-get install xyz` to install packages, but it by design has no specific knowledge of any software like apt or dpkg (and thus *cannot* set things like DEBIAN_FRONTEND=noninteractive for the user). I run commands with stdout/stderr connected to a socket, and stdin connected to /dev/null, since all commands are non-interactive and can receive no input. Generally, this results in software noticing that it cannot get input, and handling that. In a recent attempt to install a package, tzdata got pulled in as a dependency, resulting in this: ``` Setting up tzdata (2021a-1+deb11u11) ... debconf: unable to initialize frontend: Dialog debconf: (TERM is not set, so the dialog frontend is not usable.) debconf: falling back to frontend: Readline 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. Arctic 7. Atlantic 9. Indian 11. US 2. America 4. Australia 6. Asia 8. Europe 10. Pacific 12. Etc ``` And then the command hung, fruitlessly attempting to wait for input that will never arrive. debconf should detect if reading from stdin produces EOF (a zero-byte read, e.g. because it's /dev/null), and automatically switch to a noninteractive mode, rather than hanging. (In an ideal world, I'd also say that debconf should do this anytime its stdin is not a tty and it doesn't explicitly have a non-tty-requiring frontend set, rather than falling back to "readline" on a non-terminal, but I understand if this is historical behavior that'd be difficult to change for compatibility reasons. Dealing with EOF on stdin better would be the next best thing.) -- System Information: Debian Release: trixie/sid APT prefers unstable APT policy: (500, 'unstable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: arm64 Kernel: Linux 6.6.11-amd64 (SMP w/12 CPU threads; PREEMPT) Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) debconf depends on no packages. Versions of packages debconf recommends: ii apt-utils 2.7.10 pn debconf-i18n <none> Versions of packages debconf suggests: pn debconf-doc <none> pn debconf-kde-helper <none> pn debconf-utils <none> ii libgtk3-perl 0.038-3 pn libnet-ldap-perl <none> pn libterm-readline-gnu-perl <none> ii perl 5.38.2-3 ii whiptail 0.52.24-2 -- debconf information excluded
