troubles to get gdb utils working for libluajit

[hkmo]

Hi, I am just trying to use this tool, and I have some troubles:

gdb

GNU gdb (GDB) 7.6
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 "x86_64-unknown-linux-gnu".
For bug reporting instructions, please see:
http://www.gnu.org/software/gdb/bugs/.
(gdb) source luajit21.py
(gdb) lvmst
Traceback (most recent call last):
File "luajit21.py", line 597, in invoke
L = get_cur_L()
File "luajit21.py", line 127, in get_cur_L
mL = get_global_L()
File "luajit21.py", line 113, in get_global_L
gL, _ = gdb.lookup_symbol("globalL")
gdb.error: No frame selected.
Error occurred in Python command: No frame selected.

echo $PYTHONPATH

/root/uc/nginx-gdb-utils

I also updated the ~/.gdbinit with the above path.

Please let me know what is missing to get this tool working.
Also, please let me know how to use this tool in case I have a core dump on libluajit-5.1.so.

Thanks

[agentzh]

@hkmo How did you start gdb? It seems that your gdb session is not loading your core at all.

[hkmo]

By just calling gdb without any parameter.
gdb

Do you have any example of using this tool to debug libluajit or to debug lua script? That would help.
Thanks

[agentzh]

@hkmo You are running gdb in the wrong way. Gdb cannot know your executable file nor your core dump file automatically. You need to tell it:

gdb path/to/the/binary path/to/the/core