Bug#721547: libregexp-grammars-perl: Currently incompatible with Perl 5.18

[Salvatore Bonaccorso]

Package: libregexp-grammars-perl
Version: 1.028-1
Severity: serious
Tags: upstream
Justification: maintainer decision, unfit for release with perl 5.18.1; incompatible

This is a blocking bug to prevent further migration of
libregexp-grammars-perl into testing until some incompatibility
problems with Perl 5.18 are solved upstream:

,---- [ lib/Regexp/Grammars.pm ]
| Warning: Regexp::Grammars is currently unsupported under Perl 5.18.
|
| Perl 5.18 changed how 'qr' constant overloadings are parsed and the
| scope in which they are subsequently compiled. This change currently
| make it impossible to reliably create 'qr' overloadings that inject
| code blocks into a regex, as it prevents the overloaded regexes from
| compiling properly in many cases, even with an explicit 'use re
| "eval"' in scope.
|
| These problems have been reported, and the brave volunteers of P5P are
| currently working on fixes. However, these will not be available until
| at least 5.18.2.
|
| Because Regexp::Grammars relies on 'qr' overloads to inject code blocks
| into regexes, the module is curently not compatible with Perl 5.18. It
| may continue to work in some limited cases, but is no longer reliable.
|
| At present, if you rely on Regexp::Grammars for your parsing needs, your
| alternatives are either not to upgrade to Perl 5.18, to livce with the
| problems until they are resolved (in Perl 5.18.2, we hope), or else to
| consider switching to another parsing system, such as Marpa.
|
| We deeply regret that Regexp::Grammars cannot currently be maintained
| completelt due to these backwards-incompatible changes and bugs in
| Perl 5.18.
`----

Regards,
Salvatore