Bug#827075: libfile-fcntllock-perl: Provide package of File::Fcntllock::Any with no hard dependency on perlapi-*

[Dominic Hargreaves]

Package: libfile-fcntllock-perl
Version: 0.22-3
Severity: normal

Control: block -1 by 827074

#827074 discusses a proposed File::Fcntllock::Any module which uses the
XS implementation if available, otherwise falls back to the pureperl
version. This bug is to implement the required packaging split.

Quoting Niko from #677865:

> For full disclosure, if we had the fallback we could setup the
> modules something like this:
> 
>  /usr/share/perl5/File/FcntlLock.pm
>     on normal arch-independent @INC; tries ::XS first and
>     falls back to ::Pure from a special directory
> 
>  /usr/lib/<triplet>/libfile-fcntllock-perl/File/FcntllLock/Pure.pm
>     in a special directory that only File::FcntlLock knows
>     possibly with an additional symlink on the normal @INC too
> 
>  /usr/lib/<triplet>/<version>/File/FcntlLock/XS.pm (and .so)
>     on normal arch-dependent @INC
> 
> The "special directory" part would be a Debian-specific deviation
> that wouldn't need any upstream support.
> 
> This way we could honestly have the package just Recommend
> perlapi-*, and have it still work (even if in a degraded state)
> when there's version skew between Perl and the XS parts.