OT: dpkg hangs unpacking

[Toomas Tamm]

On Fri, 2012-02-10 at 09:15 +0100, Natxo Asenjo wrote:

> Have any of you guys come accross such problems? How did you tackle
> them if you did?

I have debugged several "mystery" bugs in my life, most of them
successfully. Usually it takes a lot of very primitive and tedious work.
I have not observed the situation you describe, so I cannot help with
this particular one, only give general advice.

For cases where a debugger can not be attached, adding printouts to the
software is usually the way to go.

I would start by downloading the source of package in question (dpkg,
although you may find that eventually the bug is in a different
package), and making sure you can re-compile the package and reproduce
the bug with the copy you compiled yourself.

Once this is achieved, start adding printouts to the source and, after
several rounds, find the place where it hangs. It is very likely that
this leads to another package, and then another, etc. In may cases, I
have eventually come to the conclusion that there was no bug at all,
just some kind of (mis)configuration problem.

Hoping this helps,

Toomas