Broken Perl or libc?

[Gregor Riepl <onitake@gmail.com>]

Hi,

While upgrading libc and other packages on my old Ultra 10 today, I ran
into a pretty serious problem:

Setting up libc6:sparc64 (2.30-2) ...
dpkg: error processing package libc6:sparc64 (--configure):
 installed libc6:sparc64 package post-installation script subprocess was
killed by signal (Segmentation fault)
Errors were encountered while processing:
 libc6:sparc64
E: Sub-process /usr/bin/dpkg returned an error code (1)

And this limbo situation led to:

$ apt --fix-broken install
E: Sub-process /usr/sbin/dpkg-preconfigure --apt || true received a
segmentation fault.
E: Failure running script /usr/sbin/dpkg-preconfigure --apt || true

Perl by itself works, but something in apt/dpkg seems to be broken now.

Do you have any clue where the issue could be, and how to fix it with
broken apt?

Thanks,
Gregor