Confusing conflicts with CPAN and core perl

[Evan Carroll]

Binary package hint: libio-compress-zlib-perl

Firstly, this same file is provided in two packages, perl, and libcompress-raw-zlib-perl

root@rda:/srv/DM/DM-Model# apt-file search Compress/Raw/Zlib.pm
libcompress-raw-zlib-perl: /usr/lib/perl5/Compress/Raw/Zlib.pm
perl: /usr/lib/perl/5.10.0/Compress/Raw/Zlib.pm

Ironically, if you use CPANPLUS to upgrade Compress::Raw::Zlib, it will dump over the perl file, this is because of an upstream bug I filed earlier with the way CPANPLUS is packaged in debian. Unlike CPAN, CPANPLUS is not yet configured properly by Debian. An upgrade to a core module will override any existing module packaged by perl. As if this wasn't bad enough, that module that was overriden will sit lower in the @INC stream.

So CPANPLUS will override a base-perl module with no means of brining it back, and perl won't be able to find it anyway because the perl module installed by libcompress-raw-zlib-perl will override it.

libcompress-raw-zlib-perl: /usr/lib/perl5/Compress/Raw/Zlib.pm
(version 2.011)
perl: /usr/lib/perl/5.10.0/Compress/Raw/Zlib.pm
(version 2.020)

[Evan Carroll (evancarroll)]

find an rt bug report of this http://rt.cpan.org/Public/Bug/Display.html?id=46895

[Evan Carroll (evancarroll)]

mentioned here http://www.linuxquestions.org/questions/programming-9/perl-module-compresszlib-installed-but-perl-not-detecting-it-551043/

[Evan Carroll (evancarroll)]

There is an non-issue very similar you can get if the distro updates these files to something newer than cpan. I had an old copy of Compress::Base::Common version (2.015) in /usr/local/lib/perl/5.10.0/IO/Compress/Base/Common.pm that I aparently installed (guessing here).

## A quick test to see if your affected by the issue
$ perl -MCompress::Zlib -e1
IO::Compress::Base::Common version 2.02 required--this is only version 2.015 at t line 11.
BEGIN failed--compilation aborted at /usr/share/perl5/Compress/Zlib.pm line 11.
Compilation failed in require.
BEGIN failed--compilation aborted.

Deleting /usr/local/lib/perl/5.10.0/IO/Compress/Base/Common.pm fixed this like-issue. (not the same one but it can return similar errors)

[Evan Carroll (evancarroll)]

If that above non-error happens just
rm -rf /usr/local/lib/perl/5.10.0/IO /usr/local/lib/perl/5.10.0/Compress

You will /have/ to do this if you upgrade to karmic and you have a version less than 2.020 installed on the time you upgrade.