Debug symbols not created when using cmake

Question

I compiled the c++ code library at github.com/RainerKuemmerle/g2o using cmake after adding

set(CMAKE_BUILD_TYPE Debug)

so as to be able to debug the application. Then it created a build file named "g2o". But when I try debugging with gdb, this is the output I get.

user2@arm_machine:~/g2o/trunk/bin$ gdb g2o
GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04
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 "arm-linux-gnueabihf".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /scratch/mbaxkms7/ARM_Programs_mbaxkms7/g2o/trunk/bin/g2o...(no debugging symbols found)...done.
(gdb)

Is there any other way to generate debug information while using cmake?

Answer 1

Your approach with adding set(CMAKE_BUILD_TYPE Debug) works fine.

But g2o is the program which was build with Release options. Debug version of g2o is called g2o_d. Thus to debug you need launch debugger in the following way:

user2@arm_machine:~/g2o/trunk/bin$ gdb g2o_d

Note
Different names isn't common feature of CMake but only of the g2o project:

# postfix, based on type
SET(CMAKE_DEBUG_POSTFIX "_d" CACHE STRING "postfix applied to debug build of libraries")
SET(CMAKE_RELEASE_POSTFIX "" CACHE STRING "postfix applied to release build of libraries")