Falcon new_engine doesn't start with 2013-05-13 18:17:00 (GMT) commit, the latest as of this writing. Fedora 18, x86_64.

gistfile1.txt

% gdb ./falcon
GNU gdb (GDB) Fedora (7.5.1-38.fc18)
Copyright (C) 2012 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 "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /home/miura/3rdPartyRepos/Falcon/build/bin/falcon...done.
(gdb) run -i
Starting program: /home/miura/3rdPartyRepos/Falcon/build/bin/falcon -i
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7ffff75e8700 (LWP 24108)]
[New Thread 0x7ffff6de7700 (LWP 24109)]
[New Thread 0x7ffff6ce6700 (LWP 24110)]
[New Thread 0x7ffff6be5700 (LWP 24111)]
[New Thread 0x7ffff6ae4700 (LWP 24112)]
[New Thread 0x7ffff62e3700 (LWP 24113)]
Welcome to Falcon.

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7982081 in Falcon::atomicInc (data=@0x48: <error reading variable>)
    at ../engine/mt_posix.cpp:44
44	   register int32 res = ++data;
(gdb) bt
#0  0x00007ffff7982081 in Falcon::atomicInc (
    data=@0x48: <error reading variable>) at ../engine/mt_posix.cpp:44
#1  0x00007ffff7980460 in Falcon::RefCounter<Falcon::Stream>::inc (this=0x48)
    at ../include/falcon/refcounter.h:67
#2  0x00007ffff797fcdc in Falcon::Stream::incref (this=0x0)
    at ../include/falcon/stream.h:263
#3  0x00007ffff7b61baf in Falcon::Process::inheritStreams (this=0x6f2c80)
    at ../engine/process.cpp:141
#4  0x00007ffff7b61725 in Falcon::Process::Process (this=0x6f2c80, 
    owner=0x7fffffffcc28, ms=0x0) at ../engine/process.cpp:99
#5  0x00007ffff7bcb1e2 in Falcon::VMachine::createProcess (this=0x7fffffffcc28)
    at ../engine/vm.cpp:283
#6  0x0000000000417011 in Falcon::IntMode::run (this=0x7fffffffcc20)
    at ../clt/falcon/int_mode.cpp:43
#7  0x0000000000413f19 in Falcon::FalconApp::interactive (this=0x7fffffffdc60)
    at ../clt/falcon/falcon.cpp:135
#8  0x00000000004138be in Falcon::FalconApp::guardAndGo (this=0x7fffffffdc60, 
    argc=2, argv=0x7fffffffdf58) at ../clt/falcon/falcon.cpp:101
#9  0x000000000041525a in main (argc=2, argv=0x7fffffffdf58)
    at ../clt/falcon/falcon.cpp:336
(gdb)