From vbcc release notes:
AmigaOS/68k config files include -hunkdebug, so specifying -g on the commandline is sufficient now for getting line debug info.
Line debug. No symbol hunk is generated, no variable names are saved. Debug info is path to source and line numbering. You can trace run your code and watch what happens to your real output, but you'll be unable to set watches for your vars and functions.
I know, this is of no help, sorry. I don't know a trick to get around this.