What the long option " --debug" suppose to do in bash?

Question

GNU bash, version 4.3.42(2)-release-(i686-pc-msys)
Usage:  bash [GNU long option] [option] ...
        bash [GNU long option] [option] script-file ...
GNU long options:
        --debug
        --debugger
        --dump-po-strings
        --dump-strings
        --help
        --init-file
        --login
        --noediting
        --noprofile

I notice there are two options for debug of my bash script. since I'm new to bash, I really want a debugger or things like that.

I have searched official document about bash 4.3, but I still don't know what the "--debug" long option suppose to do.

Answer 1

Looking at the source code, --debug sets a debugging flag (in shell.c), but I can't find anywhere that flag is used. So it appears to not do anything.

--debugger activates support features for the bash debugger; the latter is probably what you're looking for.