I open Clewn normally, add a breakpoint at the start of the program and try running it. I get a warning:
"warning: GDB: Failed to set controlling terminal: Operation not permitted"
And an error:
"Error in re-setting breakpoint 1: Function "/home/XXXX/Dropbox/Projects/C++/Jumping Into C++/Examples/45 bug2/bug2.cpp:18" not defined."
And the program fails to halt, immediately giving me the output:
"[Inferior 1 (process 3345) exited normally]"
Bizarrely, Clewn worked the first time I tried using it but has failed all subsequent times. I've looked into the gdb error and it seems to be a netbeans problem (http://forums.netbeans.org/post-64235.html) related to not using KDE, I'm not using KDE, but I'm not using Gnome either, I'm using LXDE. With the lxterminal.
The advice given on the netbeans thread advise using the output window to select Project properties-> Run->Console type and setting it to "output window". I'm obviously not using the Netbeans IDE so that's a bit of a non-starter.
I'm attaching the full output of the gdb window in Clewn.
Full output of gdb window in Clewn
With a little further investigation the problem appears not to be the warning about the terminal but a problem with recent versions of GDB and paths with spaces in them, see here: http://sourceware.org/bugzilla/show_bug.cgi?id=13798
I've tested it and sure enough running Clewn in a directory without spaces makes it work again.