Bug#807756: gnubg: fails to start. hangs using 100% of one cpu core

[Andreas Metzler]

On 2015-12-12 Russ Allbery <rra at debian.org> wrote:
[...]
> > when starting gnubg it uses 100% of one cpu core and then apparently
> > hangs with no output and without starting the gui.

> So, I'm not sure what's going on here, but it seems to be some sort of
> weird bug in libgnutls/libtasn1.  gnubg is going into an infinite loop
> before any gnubg code actually runs at all, during shared library
> initialization.  This is the backtrace of the infinite loop:
[...]

Some more points of strangeness:
jessie's gnubg package (1.04.000-1) works on current stretch.
Rebuilding the jessie source on current sid produces a binary which
fails.
Rebuilding with DEB_BUILD_OPTIONS=noopt works
Rebuilding on current sid with gcc-4.9 produces a working package.
Rebuilding either the jessie or the sid source with -O1 segfaults at
start:
(gdb) run
Starting program: /usr/games/gnubg
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
memcpy (__dest=0x833070,
    __dest at entry=<error reading variable: DWARF-2 expression error: Loop detected (257).>, __src=0x7fffea09a46e,
    __src at entry=<error reading variable: DWARF-2 expression error: Loop detected (257).>, __len=6,
    __len at entry=<error reading variable: DWARF-2 expression error: Loop detected (257).>) at /usr/include/x86_64-linux-gnu/bits/string3.h:53
53


cu Andreas
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