Debugging requires:
-D --verbose -T
as the README file says...
[2012-02-07 07:49:21] Started cgminer 2.2.3
...
[2012-02-07 07:49:21] CompilerOptions: -D WORKSIZE=64 -D VECTORS4 -D BITALIGN -D BFI_INT
[2012-02-07 07:49:21] Error: Building Program (clBuildProgram)
[2012-02-07 07:49:21]
[2012-02-07 07:49:21] Failed to init GPU thread 0, disabling device 0
...
cgminer crashed
are missing.