From @jonathanstowe

Hi,
there is, to me anyway, an unexpected change in behaviour between 2015.11-163-g2897239 and 2015.11-347-g47d2daf . If it is expected then I am quite happy to accept that (with the behaviour documented,) but it does look unintended to me.

Given TR.pm​:

module TR {
  multi sub trait_mod​:<is> (Attribute​:D $a, :$some-trait!) is export {
  }
}

And Foo.pm​:

class Foo {
  use TR;
  multi sub trait_mod​:<is> (Attribute $a, :$other-trait) is export {
  }
}

Then "tr"​:

use Foo;

class Womble {
  has $.foo is other-trait;
}

results (in the latter revision)​:

Can't use unknown trait 'is other-trait' in an attribute declaration.
at /home/jonathan/devel/perl6/tr​:4
  expecting any of​:
  rw
  readonly
  box_target
  leading_docs
  trailing_docs

But moving the "use TR;" outside the Foo class block makes the trait from within Foo to be recognised. It works in both ways in the 2015.11-163-g2897239

This does have ecosystem implications (see e.g. tadzik/JSON-Unmarshal#14 ) so if it is actually a conscious change in behaviour (and not an unintended consequence of some other change,) it probably needs to be clearly documented somewhere.

Thanks.

From @jonathanstowe

Just bisected this on rakudo-moar and it appears that​:

87288285f6f398ec7cba0900312ced4b580d79ed is the first bad commit
commit 87288285f6f398ec7cba0900312ced4b580d79ed
Author​: Stefan Seifert <nine@​detonation.org>
Date​: Sat Nov 14 10​:43​:38 2015 +0100

  Have Repository​::FileSystem automatically precompile files
 
  We now precompile loaded modules automatically. However, we cannot do this
  anymore as soon as we encounter a 'use lib' as this changes the precompilation
  store used. Consider​:
  use Test;
  use lib 'foo';
  use Test​::Util; # which again uses Test
  Test​::Util would be loaded from a different precompilation store that contains
  a different precompiled version of Test to the one already loaded.

:040000 040000 67079ac3caa0dea4eab121fa09edfcd14306559c 48e40ca79a4922c6fa912cfd387235e5ddd6f258 M src

Not quite sure where that leaves us.

From @jonathanstowe

It appears (as suggested by nine on IRC,) that changing the 'tr' to​:

use Test;
use lib '.';
use Foo;

class Womble {
  has $.foo is other-trait;
}

and running it without a '-I.' gets rid of the error, this would suggest there may have been a pre-existing pre-compilation problem, that got exposed when everything was precompiled again.

From @jonathanstowe

This is stll present as of Rakudo version 2016.03-110-g5bfc8fb built on MoarVM version 2016.03-104-g10d397