Debugging at C++ level can be done using any standard debugger. The following macro for gdb makes it easier to see what happens in Tcl-based subroutines:
## for Tcl code define pargvc set $i=0 while $i \< argc p argv[$i] set $i=$i+1 end end document pargvc Print out argc argv[i]'s common in Tcl code. (presumes that argc and argv are defined) end