libtask-weaken-perl binary package in Ubuntu Precise amd64

 One recurring problem in modules that use Scalar::Util's weaken function is
 that it is not present in the pure-perl variant.
 .
 While this isn't necesarily always a problem in a straight CPAN-based Perl
 environment, some operating system distributions only include the pure-Perl
 versions, don't include the XS version, and so weaken is then "missing" from
 the platform, despite passing a dependency on Scalar::Util successfully.
 .
 Most notably this is RedHat Linux at time of writing, but other come and go
 and do the same thing, hence "recurring problem".
 .
 The normal solution is to manually write tests in each distribution to ensure
 that weaken is available.

Source package