[Debconf-devel] Bug#985572: debconf: please test for the usability of the debconf frontends

[Aurelien Jarno]

On 2021-03-20 10:25, Aurelien Jarno wrote:
> On 2021-03-04 19:26, Thomas Hahn wrote:
> > Package: libc6
> > Version: 2.28-10
> > Severity: normal
> > X-Debbugs-Cc: thahn01 at t-online.de
> > 
> > Dear Maintainer,
> > 
> > installed buster, then apt upgrade  was also fine,
> > but the following dist-upgrade put the system in a broken state.
> > 
> > Preparing to unpack .../62-locales_2.31-9_all.deb ...
> > Unpacking locales (2.31-9) over (2.28-10) ...
> > Preparing to unpack .../63-openssh-server_1%3a8.4p1-4_amd64.deb ...
> > Unpacking openssh-server (1:8.4p1-4) over (1:7.9p1-10+deb10u2) ...
> > Preparing to unpack .../64-libc6_2.31-9_amd64.deb ...
> > whiptail: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.29' not found (required by /lib/x86_64-linux-gnu/libslang.so.2)
> > debconf: whiptail output the above errors, giving up!
> 
> debconf has a nice fallback mechanism that switches back to a "lower"
> frontend in case the selected one is unavailable. However this mechanism
> only checks for the availability of the binary, not its usability.
> Running $frontend --version for example would test that it is actually
> executable. While it is definitely not a fix for the reported issue
> above, it would definitely improve the user experience.
> 
> By the way, I have noticed that their is support for the Xdialog
> frontend, but it seems that in practice no package is providing this
> binary.

Please note that this is already implemented in cdebconf. If whiptail
installed but not usable, it fallbacks to readline.

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien at aurel32.net                 http://www.aurel32.net