[Debconf-devel] Bug#425397: tasksel/pkgsel causing Etch netboot install to hang indefinitely

[Adrian Bridgett]

Many thanks :-)  I've not been in a position to retest this yet,
however I'm hitting what looks like a very similar problem which the
new package doesn't help with.  All the comments below are w.r.t
debconf 1.5.14.  Apologies for the rambling nature, but maybe some
random comment may spark something...

I've been putting loads of debug output in but my understanding of how
the whole package sits together isn't good enough to figure out what
should happen.  /usr/share/doc/debconf-doc/passthrough.txt.gz for
example was really helpful, but I'm not sure how dpkg-preconfigure
(and debconf-apt-progress) fits into it.

I'm using puppet at the end of a preseeded install and some packages
keep hanging (sysstat and postfix namely).  I suspect it's the
preseeding that's causing the problem.  

What I see is dpkg-preconfigure running /tmp/postfix.config.12345
(sometimes with a zombie'd process in the middle).  dpkg-preconfigure
is reading from FD8 (which is FD1 from the postfix.config),  the
postfix-config in turn is reading from FD0 (which is FD7 from the
dpkg-preconfigure).  Deadlock ensues :-(

I've been trying to do some debugging but it's a bit tricky as I'm not
sure exactly which frontends etc end up being run.  puppet is calling
apt which is set to run dpkg-preconfigure, overall therefore, the
config file thus gets run once by dpkg-preconfigure and once normally.

When postfix.config runs /usr/share/debconf/confmodules, at line 45 it
complains that FD3 is a bad file descriptor.  Listing /proc/$$/fd
shows that FD3 doesn't exist.  FD2 points to the overall stderr, FD1
is a pipe back to FD8 of dpkg-preconfigure.  FD0 is FD7 from
dpkg-preconfigure.

FD3 exists and DEBCONF_REDIR is set when ConfModule::startup() is
called, however it looks like FD3 does not persist into the open2()
call.  I'll try and post a bit more tomorrow after more debugging...

Adrian
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