My investigations indicate that it is still true that as per Debian bug
report (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=403304)
--debugger does NOT start the debugger UNLESS the debugged script has a
$1. For example
/bin/bash --debugger -- ~/scripts/ex1.sh
will just run the script but
/bin/bash --debugger -- ~/scripts/ex1.sh XXX
will enter the debugger. To comment on the other prior information on
the Debian bug report:
1. The upstream bashdb developer is correct that checking "strings
`which bash` | grep bashdb" is a good test for whether bash will find
bashdb-main.inc, but this is not relevant to Debian becase this is set
correctly in Debian's case.
2. If you take an upstream tarball of bash and compile it then even the
extra $1 will not make the debugger run under that bash, unless you link
the upsteram location of '/usr/local/share/bashdb' to the Debian value
of /usr/share/bashdb.
In other words the other commenters were correct but had not got to the
root issue. The root issue is appears to be this line in shell.c in the
bash code:
if (debugging_mode && locally_skip_execution == 0 && running_setuid
== 0 && dollar_vars[1])
start_debugger ();
I enclose a patch that I believe would address this, and suggest it is
an upstream bash issue.
Description: correct check on $0 in conditions for entering debugger
Author: Nicholas Bamber <nicho...@periapt.co.uk>
Bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=403304
Last-Update: 2015-10-12
Index: bash-4.3/shell.c
===================================================================
--- bash-4.3.orig/shell.c
+++ bash-4.3/shell.c
@@ -720,7 +720,7 @@ main (argc, argv, env)
/* Bind remaining args to $1 ... $n */
arg_index = bind_args (argv, arg_index, argc, 1);
- if (debugging_mode && locally_skip_execution == 0 && running_setuid == 0 && dollar_vars[1])
+ if (debugging_mode && locally_skip_execution == 0 && running_setuid == 0 && dollar_vars[0])
start_debugger ();
/* Do the things that should be done only for interactive shells. */
