use Fatal qw(:lexical) throws autodie::exception

[nthykier]

After a bit of testing (see commit dc33f2b), it turns out that the code:

use Fatal qw(:lexical open);

open(my $fd, '<', 'missing-file');

Thows an exception like "use autodie qw(open)" would have (in fact said exception is an autodie::exception). Using git bisect, I have determined this has happened since commit 54d2fbd, so this behaviour has been defacto standard since 2008. This leads to the question: If we separate autodie from Fatal (issue #60), how should "use Fatal qw(:lexical ...)" behave? I see the following options:

1. Keep existing behaviour by "promoting" it to "autodie" (i.e. make use "Fatal qw(:lexical ... );" basically the same as "use autodie qw(...);").
2. Have "use Fatal qw(:lexical ...);" throw "old-style" exceptions.
3. Remove support for ":lexical" in Fatal completely (possibly with a "grace period" filled with deprecation warnings).

Note that the "Fatal" POD does not mention the ":lexical" tag at all (but it used to do). I suspect this to be by intention as the documentation suggests Fatal to be deprecated in favor of autodie. This begs the question, is ":lexical" now just an implementation-detail that we can change at will?

@pjf: Any suggestions? Otherwise, I will probably go with 1. as it seems to be the "most backwards compatible" option, given the lifetime of this bug.

[pjf]

I'd suggest either 1 or 3, both are relatively safe. '3' means that :lexical becomes a compile-time error, which means there's much less of there being surprises for our users, whereas '1' means nothing changes at all.

I'm not sure any code out there actually uses :lexical. It was very much there as a potential interface, which was obviously dropped in favour of the autodie pragma.

So either 1 or 3; if in doubt, I agree with 1, as it won't cause any problems no matter what crazy things our users have done. :)

~ Paul

[nthykier]

Ok, I think I will go with 1) and deprecate the usage of "use Fatal qw(:lexcial)", so we can eventually implement 3). Thanks for your remarks. :)