Bug#297607: dpkg-reconfigure exim4-config hangs, blocks debian installation

[Joey Hess]

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Package: exim4-config
Version: 4.50-2
Severity: grave
Justification: breaks debian installation

base-config runs a dpkg-reconfigure exim4-config as part of the Debian
installation process so users get a chance to configure exim, which is
initially installed noninteractively by debootstrap.

With this new version now in unstable, I've noticed that my all my daily
debian automatic installation tests of unstable installs have begin to
fail, because the dpkg-reconfigure run hangs after the questions are
asked. This is easy to reproduce:

cow:/home/joey# dpkg-reconfigure exim4-config
Restarting MTA: exim4.

It will never return to the prompt. ps shows this:

 4547 pts/1    S+     0:01  |                   \_ /usr/bin/perl -w /usr/sb=
in/dp
 4554 pts/1    Z+     0:00  |                       \_ [exim4-config.] <def=
unct>

Strace of the debconf process (4547) shows it blocked in read from fd 8:

cow:/home/joey# strace -p 4547
Process 4547 attached - interrupt to quit
read(8,=20

I assume this is some sort of debconf/daemon interaction problem. The proce=
ss
tree also has an exim daemon running at this point. If I kill it, deconf st=
ops
blocking and returns. Presumably the code that runs this daemon no longer
takes care to close file descriptors connected to debconf.

FWIW, this system has debconf 1.4.46 installed.=20

--=20
see shy jo

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