[bug-gettext] msgfmt segfault under qemu-arm, Jessie only

[John Morris]

The `msgfmt` executable segfaults  only under `qemu` (`armhf`; other 
arches untested) and only in Debian Jessie (package v. 0.19.3-2).

    # schroot -u root -c jessie-armhf-sbuild -- \
        qemu-arm-static /usr/bin/msgfmt
    qemu: uncaught target signal 11 (Segmentation fault) - core dumped
    E: Child terminated by signal ‘Segmentation fault’

The same thing works fine in Ubuntu Trusty, so my first thought was to 
rebuild that package v. 0.18.3.1-1ubuntu3 for Jessie.  However, that 
version segfaults, too.  So, apparently not a regression in `gettext`.

I also tried attaching a debugger, remotely, as required by `qemu`, but 
this didn't work well; log below.  Maybe it's qemu that's crashing.

At least one other person has run across the `msgfmt`/`qemu` problem. 
He believes it's due to `pthreads`, but if so I'm surprised not many 
more have encountered it.  Link:

    http://samnazarko.co.uk/2014/07/git-under-arm-emulated-environments/

Have list members encountered this before?  Any advice on where to start 
digging next?  Thanks-

        John



    # schroot -u root -c jessie-armhf-sbuild -- \
            qemu-arm-static -g 1234 /usr/bin/msgfmt &
    [1] 26056
    # arm-none-eabi-gdb \
            -directory 
chroots/jessie-armhf/build/gettext-kJWpdX/gettext-0.18.3.1 \
            -ex 'set sysroot chroots/jessie-armhf' \
            -ex 'target remote localhost:1234' \
            chroots/jessie-armhf/usr/bin/msgfmt
    GNU gdb (7.6.50.20131218-0ubuntu1+1) 7.6.50.20131218-cvs
    Copyright (C) 2013 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later 
<http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.  Type "show 
copying"
    and "show warranty" for details.
    This GDB was configured as "--host=x86_64-linux-gnu 
--target=arm-none-eabi".
    Type "show configuration" for configuration details.
    For bug reporting instructions, please see:
    <http://www.gnu.org/software/gdb/bugs/>.
    Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.
    For help, type "help".
    Type "apropos word" to search for commands related to "word"...

    warning: A handler for the OS ABI "GNU/Linux" is not built into 
this configuration
    of GDB.  Attempting to continue with the default arm settings.

    Reading symbols from chroots/jessie-armhf/usr/bin/msgfmt...done.
    Remote debugging using localhost:1234
    warning: A handler for the OS ABI "GNU/Linux" is not built into 
this configuration
    of GDB.  Attempting to continue with the default arm settings.

    0xf67d6bc0 in ?? ()
    (gdb) bt
    bt
    #0  0xf67d6bc0 in ?? ()
    #1  0x00000000 in ?? ()
    (gdb) c
    c
    Continuing.
    Cannot access memory at address 0x0

    Program received signal SIGSEGV, Segmentation fault.
    0xf6376f50 in ?? ()
    (gdb) bt
    bt
    #0  0xf6376f50 in ?? ()
    #1  0xf62e57fe in ?? ()
    Backtrace stopped: previous frame identical to this frame (corrupt 
stack?)
    (gdb)