I installed 5.20 (64bitall threaded longdouble) on OpenSUSE 13.1

Linux 3.11.10-11-desktop [openSUSE 13.1 (Bottle)]  x86_64 Xeon(R) CPU 
+E3-1245 V2 @ 3.40GHz/3672(8) x86_64  11914 Mb
This is perl 5, version 20, subversion 0 (v5.20.0) built for x86_64-li
+nux-thread-multi-ld
[download]

I managed to get most of my 5.18.2 installed modules also installed under 5.20. Some needed answering questions I did not (yet) have available in my cpanprefs and others needed patches I had done before but did not store other than in the RT ticket that was already filed for the module. What is left uninstallable is the list below.

XML::LibXML::PrettyPrint from tobyink was manually changed to replace the useless dependency on common::sense (useless as it adds no value over using strict, and adds a dependency on a module that is blocked in my cpanprefs), with strict.

Devel::Size        - size mismatch. Analysis done by DaveM
Image::Magick        - hangs in mpeg/read.t test
JE            - several issues ($^T, $^W, regex)
Lingua::Translate    - babelfish redirect (no perl problem)
MooseX::App::Cmd    - test fail
POE::Loop::Tk        - Cannot redirect out of tied STDIN
Statistics::LineFit    - longdouble issues in test (bad test case)
SVN::Core        - make fails due to svn incompat
[download]

failing for failing dependency:

WWW::Scripter::Plugin::Ajax        - depend on JE
WWW::Scripter::Plugin::JavaScript    - depend on JE
[download]

the 5.20.0 tree now has 9048 .pm files based on 818 releases installed from cpan after the initial install.

I'd call that a success.