Hi all.

I've found that the perl debugger 'v' command fails since I upgraded a
while ago.

It's OK on Mint 20.3 (perl 5.30) but broken on Mint 21 (perl 5.34).

I get this:
Enter h or 'h h' for help, or 'man perldebug' for more help.

main::(/tmp/t.pl:1): print "hello\n";
DB<1> v

Undefined subroutine &DB::cmd_l called at
/usr/share/perl/5.34/perl5db.pl line 6034.
at /usr/share/perl/5.34/perl5db.pl line 6034.
DB::cmd_v("v", "", 1) called at /usr/share/perl/5.34/perl5db.pl line 4798
DB::cmd_wrapper("v", "", 1) called at /usr/share/perl/5.34/perl5db.pl
line 4311
DB::Obj::_handle_cmd_wrapper_commands(DB::Obj=HASH(0x55f4251379a0))
called at /usr/share/perl/5.34/perl5db.pl line 3200
DB::DB called at /tmp/t.pl line 1
Debugged program terminated. Use q to quit or R to restart,
use o inhibit_exit to avoid stopping after program termination,
h q, h R or h o to get additional info.

Indeed, cmd_l is not defined in the current perl5db.pl script.

Has no-one else noticed this? Any fix? - otherwise I'll have to copy
over the older script (or part of it!).

Thanks.

--
Mike Scott
Harlow, England

On 08/11/2023 21:04, Mike Scott wrote:
> Hi all.
>
> I've found that the perl debugger 'v' command fails since I upgraded a
> while ago.
>
> It's OK on Mint 20.3 (perl 5.30) but broken on Mint 21 (perl 5.34).
>
> I get this:
> Enter h or 'h h' for help, or 'man perldebug' for more help.
>
> main::(/tmp/t.pl:1):    print "hello\n";
>   DB<1> v
>
> Undefined subroutine &DB::cmd_l called at
......
> Indeed, cmd_l is not defined in the current perl5db.pl script.
>

I find this really weird; somehow someone's gratuitously removed a
complete 4-line subroutine and nobody noticed.

Anyway, I copied the relevant lines from an older version, and it seems
to work now.

In perl5db.pl, add
sub cmd_l {
my (undef, $line) = @_;

return _cmd_l_main($line);
}

after the (badly worded) comment
## end sub cmd_l

(X-posted to c.l.p.misc in case anyone there is interested.)

--
Mike Scott
Harlow, England

Mike Scott <usenet.16@scottsonline.org.uk.invalid> writes:
> On 08/11/2023 21:04, Mike Scott wrote:
>> Hi all.
>> I've found that the perl debugger 'v' command fails since I upgraded
>> a while ago.
>> It's OK on Mint 20.3 (perl 5.30) but broken on Mint 21 (perl 5.34).
>> I get this:
>> Enter h or 'h h' for help, or 'man perldebug' for more help.
>> main::(/tmp/t.pl:1):    print "hello\n";
>>   DB<1> v
>> Undefined subroutine &DB::cmd_l called at
> .....
>> Indeed, cmd_l is not defined in the current perl5db.pl script.
>
> I find this really weird; somehow someone's gratuitously removed a
> complete 4-line subroutine and nobody noticed.
>
> Anyway, I copied the relevant lines from an older version, and it
> seems to work now.
>
> In perl5db.pl, add
> sub cmd_l {
> my (undef, $line) = @_;
>
> return _cmd_l_main($line);
> }
>
> after the (badly worded) comment
> ## end sub cmd_l
>
>
> (X-posted to c.l.p.misc in case anyone there is interested.)

This seems to be the relevant commit in https://github.com/perl/perl5 :

commit b7a96fc9f5394c34d86d8b476ef4293f81ce341b
Author: [omitted]
Date: 2020-03-31 16:45:04 +1100

fix `l $var` where $var is a lexical variable

As with `i $obj` the DB::Obj in the call stack prevented DB::eval
from compiling/executing in the context of the debugged code.

I've omitted the author's name, but it's easy enough to look up.
The commit is over 5000 lines. I haven't studied the changes.

`sub cmd_l` is present in 5.33.0, absent in 5.33.1 and later and in
5.34.0 and later.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Will write code for food.
void Void(void) { Void(); } /* The recursive call of the void */