Bug #93153 for Moo: Moo does not like constructors with prototypes

Tue Feb 18 20:30:39 2014 CRZEDPSYC [...] cpan.org - Ticket created

Subject:

Moo does not like constructors with prototypes

Moo fails when extending a non-Moo class with a prototype `()` on its constructor. Prototype mismatch: sub main::new () vs none at .../Moo/_Utils.pm line 84. A test case: { package My::Base; sub new () { my $class = shift; bless {}, $class; } 1; } use Moo; extends 'My::Base'; 1; This is using Moo==1.004002, Perl v5.18.2.

Fri Feb 21 11:04:28 2014 CRZEDPSYC [...] cpan.org - Broken in 1.003000 added

Fri Feb 21 11:04:34 2014 CRZEDPSYC [...] cpan.org - Broken in 1.003001 added

Fri Feb 21 11:04:34 2014 CRZEDPSYC [...] cpan.org - Broken in 1.004000 added

Fri Feb 21 11:04:34 2014 CRZEDPSYC [...] cpan.org - Broken in 1.004001 added

Fri Feb 21 11:04:34 2014 CRZEDPSYC [...] cpan.org - Broken in 1.004002 added

Fri Feb 21 11:06:41 2014 CRZEDPSYC [...] cpan.org - Correspondence added

I bisected this with my test above, and found: # first bad commit: [85de1ef9dedd1a60115e475036dabaed68dc6ae2] fix FOREIGNBUILDARGS not being called when no attributes created i.e. broken in this commit.

Fri Feb 21 13:07:58 2014 haarg [...] haarg.org - Correspondence added

On Fri Feb 21 11:06:41 2014, CRZEDPSYC wrote: Show quoted text

> I bisected this with my test above, and found: > # first bad commit: [85de1ef9dedd1a60115e475036dabaed68dc6ae2] fix > FOREIGNBUILDARGS not being called when no attributes created > > i.e. broken in this commit.

That commit doesn't have anything to do with the root cause of this. If your subclass includes attributes, you'll see the breakage in earlier versions. The root cause is a perl bug in its handling of the inheritance cache. I've added a workaround which will be in the next Moo release. Aside from that though, the prototype being used is really broken. Prototypes don't effect method calls, and if they did that would be specifying that ->new accepted no parameters, when it clearly accepts at least the class name.

Fri Feb 21 13:07:59 2014 The RT System itself - Status changed from 'new' to 'open'

Fri Feb 21 13:10:57 2014 haarg [...] haarg.org - Status changed from 'open' to 'patched'

Fri Feb 21 13:10:57 2014 haarg [...] haarg.org - Broken in 1.003000 deleted

Fri Feb 21 13:10:58 2014 haarg [...] haarg.org - Broken in 1.003001 deleted

Fri Feb 21 13:10:58 2014 haarg [...] haarg.org - Broken in 1.004000 deleted

Fri Feb 21 13:10:59 2014 haarg [...] haarg.org - Broken in 1.004001 deleted

Fri Feb 21 13:26:10 2014 CRZEDPSYC [...] cpan.org - Correspondence added

Show quoted text

> I've added a workaround which will be in the next Moo release.

Excellent - thanks. Show quoted text

> Aside from that though, the prototype being used is really broken.

Yes, this arose when extending Curses::UI::* -- not my code. I would have added a ticket over there, but Moo used to handle the particular case fine, and Moose still does.

Sat May 24 13:22:23 2014 haarg [...] haarg.org - Correspondence added

The fix for this is in the latest stable release.

Sat May 24 13:22:26 2014 haarg [...] haarg.org - Status changed from 'patched' to 'resolved'

Sat May 24 13:22:27 2014 haarg [...] haarg.org - Fixed in 1.004005 added