Instead we may want to have some better output, maybe?

print_trace:  Obtained 21 stack frames.
print_trace:  Obtaining symbols now done.
./src(print_trace+0x12) [0x43f572]
/usr/lib/libpthread.so.0(+0xf0e0) [0x7fccc50110e0]
./src(list_move+0x7) [0x459a77]
./src(teleport_enemy+0x68) [0x443008]
./src() [0x42630c]
/usr/lib/liblua.so.5.2(+0xcd95) [0x7fccc54c2d95]
/usr/lib/liblua.so.5.2(+0x18084) [0x7fccc54ce084]
/usr/lib/liblua.so.5.2(+0xc6bc) [0x7fccc54c26bc]
/usr/lib/liblua.so.5.2(lua_resume+0x44) [0x7fccc54c30d4]
./src(resume_lua_coroutine+0x11) [0x4266b1]
./src(chat_run+0x1b3) [0x457223]
./src() [0x43da93]
./src(move_tux+0x68d) [0x43c45d]
./src(Game+0xcf) [0x44a05f]
./src(TestMap+0x28) [0x46fda8]
./src(DoLevelEditorMainMenu+0xab8) [0x476768]
./src(leveleditor_process_input+0x6e1) [0x474791]
./src(LevelEditor+0x35) [0x46fe05]
./src(main+0x155) [0x4145a5]
/usr/lib/libc.so.6(__libc_start_main+0xf5) [0x7fccc4a17a15]
./src() [0x41465d]

print_trace():  received SIGSEGV!


addr2line -e ./src/freedroidRPG 0x43f572 0x459a77 0x443008 0x42630c 0x4266b1
0x457223 0x43da93 0x43c45d 0x44a05f 0x46fda8 0x476768 0x474791 0x46fe05 0x4145a5
0x41465d
/home/matthias/vcs/git/freedroid/src/misc.c:387
/home/matthias/vcs/git/freedroid/src/lists.c:65
/home/matthias/vcs/git/freedroid/src/enemy.c:211
/home/matthias/vcs/git/freedroid/src/lua.c:147
/home/matthias/vcs/git/freedroid/src/lua.c:1490
/home/matthias/vcs/git/freedroid/src/chat.c:826
/home/matthias/vcs/git/freedroid/src/action.c:544
/home/matthias/vcs/git/freedroid/src/influ.c:604
/home/matthias/vcs/git/freedroid/src/main.c:106
/home/matthias/vcs/git/freedroid/src/lvledit/lvledit.c:252
/home/matthias/vcs/git/freedroid/src/lvledit/lvledit_menu.c:1054
/home/matthias/vcs/git/freedroid/src/lvledit/lvledit_input.c:193
/home/matthias/vcs/git/freedroid/src/lvledit/lvledit.c:282
/home/matthias/vcs/git/freedroid/src/main.c:185
??:?

at 422621c070fd1162d5f801ff47d65c92a8d4533b

That's pretty normal. Terminal is not a bot and use a dummy bot while dialog. You 
can't teleport that dummy bot.

Can we "blacklist" some lua functions for obstacles?

Moving to minor:
1) issue does not affect current game (to reproduce you have to write code)
2) issue only affects dialogs with dummy bots (i.e. for objects)