Re: signal SIGSEGV, Segmentation fault

[Andreas Höschler]

Hi Josh,

On May 3, 2018, at 2:45 PM, Andreas Höschler wrote:

Segmentation fault
...
while accessing one of its instance variables, actually in the

     NSLog(@"routeVisible: %d", _routeVisible);

line. When I comment this line out I get the same error in the next line while accessing _routePath and so on. I am clueless how to fix this. The code works on MacOSX and also with on an ancient GNUstep/Debian/Kubuntu setup. Any idea what might cause this trouble on Ubuntu 16.04 with the latest GNUstep or how to further track this down?

  Currently, libobjc2's non-fragile ABI can cause segfaults on Debian-based distros (& perhaps other Linux distros) when directly accessing some class' instance variables.

  There's a few workarounds for Ubuntu:

* The Ubuntu install script on the wiki has a workaround (it checks out an old version of GNUstep-make that builds using the fragile ABI):
http://wiki.gnustep.org/index.php/GNUstep_under_Ubuntu_Linux

* If you need the non-fragile ABI, there's a script + objc2-patch attached to this list message:
http://lists.gnu.org/archive/html/discuss-gnustep/2017-12/msg00129.html

* David is working on a new ABI, and you can try his experimental builds:
http://lists.gnu.org/archive/html/gnustep-dev/2018-04/msg00051.html

Thanks so much. That was the solution for my problem. The following lines extracted from your script got me a working GNUstep environment:

apt-get install git-core

git --version

cd /usr/src/GNUstep

git clone https://github.com/gnustep/tools-make.git

cd tools-make

git checkout `git rev-list -1 --first-parent --before=2017-04-06 master`

./configure --enable-debug-by-default --with-layout=gnustep

. /usr/GNUstep/System/Library/Makefiles/GNUstep.sh

cd libs-base-master

make distclean

./configure

make

make install

cd ..

cd libs-gui-master

make distclean

./configure

make

make install

cd ..

cd libs-back-master

make distclean

./configure

make

make install

cd ..

The standard installation without the make hack simply does not work at all on Ubuntu 16! :-(

Thanks so much,

 Andreas