eellis@eellis-ws ~ $ perl -v

This is perl 5, version 20, subversion 2 (v5.20.2) built for x86_64-linux
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2015, Larry Wall

Perl may be copied only under the terms of either the Artistic License or the
GNU General Public License, which may be found in the Perl 5 source kit.

Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl".  If you have access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.

eellis@eellis-ws ~ $ perlbrew list
* perl-5.20.2
eellis@eellis-ws ~ $ perlbrew list-modules
Algorithm::Diff
Encode::Locale
File::Listing
HTML::Parser
HTML::Tagset
HTTP::Cookies
HTTP::Daemon
HTTP::Date
HTTP::Message
HTTP::Negotiate
IO::HTML
LWP
LWP::MediaTypes
Net::HTTP
PadWalker
Perl
Spiffy
Tcl
Test::Base
Test::YAML
Text::Diff
Tkx
URI
WWW::RobotRules
XML::Parser
XML::Twig
YAML
YAML::AppConfig
YAML::Syck
eellis@eellis-ws ~ $ cpan install JSON
Reading '/home/eellis/.cpan/Metadata'
  Database was generated on Wed, 02 Sep 2015 06:53:25 GMT
Running install for module 'JSON'
Checksum for /home/eellis/.cpan/sources/authors/id/M/MA/MAKAMAKA/JSON-2.90.tar.gz ok
Configuring M/MA/MAKAMAKA/JSON-2.90.tar.gz with Makefile.PL
Welcome to JSON (v.2.90)
=============================


 *************************** CAUTION **************************************
 *                                                                        *
 * INCOMPATIBLE CHANGE (JSON::XS version 2.90)                            *
 *                                                                        *
 * JSON.pm had patched JSON::XS::Boolean and JSON::PP::Boolean internally *
 * on loading time for making these modules inherit JSON::Boolean.        *
 * But since JSON::XS v3.0 it use Types::Serialiser as boolean class.     *
 * Then now JSON.pm breaks boolean classe overload features and           *
 * -support_by_pp if JSON::XS v3.0 or later is installed.                 *
 *                                                                        *
 * JSON::true and JSON::false returned JSON::Boolean objects.             *
 * For workaround, they return JSON::PP::Boolean objects in this version. *
 *                                                                        *
 *     isa_ok(JSON::true, 'JSON::PP::Boolean');                           *
 *                                                                        *
 * And it discards a feature:                                             *
 *                                                                        *
 *     ok(JSON::true eq 'true');                                          *
 *                                                                        *
 * In other word, JSON::PP::Boolean overload numeric only.                *
 *                                                                        *
 *     ok( JSON::true == 1 );                                             *
 *                                                                        *
 **************************************************************************


 ************************** CAUTION **************************
 * This is 'JSON version 2' and there are many differences   *
 * to version 1.xx                                           *
 * Please check your applications useing old version.        *
 *   See to 'INCOMPATIBLE CHANGES TO OLD VERSION' and 'TIPS' *
 *************************************************************


Checking if your kit is complete...
Looks good
Generating a Unix-style Makefile
Writing Makefile for JSON
Writing MYMETA.yml and MYMETA.json
  MAKAMAKA/JSON-2.90.tar.gz
  /home/eellis/perl5/perlbrew/perls/perl-5.20.2/bin/perl Makefile.PL INSTALLDIRS=site -- OK
Running make for M/MA/MAKAMAKA/JSON-2.90.tar.gz
cp lib/JSON.pm blib/lib/JSON.pm
cp lib/JSON/backportPP/Compat5005.pm blib/lib/JSON/backportPP/Compat5005.pm
cp lib/JSON/backportPP/Boolean.pm blib/lib/JSON/backportPP/Boolean.pm
cp lib/JSON/backportPP.pm blib/lib/JSON/backportPP.pm
cp lib/JSON/backportPP/Compat5006.pm blib/lib/JSON/backportPP/Compat5006.pm
Manifying blib/man3/JSON.3
Manifying blib/man3/JSON::backportPP.3
Manifying blib/man3/JSON::backportPP::Boolean.3
Manifying blib/man3/JSON::backportPP::Compat5005.3
Manifying blib/man3/JSON::backportPP::Compat5006.3
  MAKAMAKA/JSON-2.90.tar.gz
  /usr/bin/make -- OK
Running make test
PERL_DL_NONLAZY=1 /home/eellis/perl5/perlbrew/perls/perl-5.20.2/bin/perl "-MExtUtils::Command::MM" "-MTest::Harness" "-e" "undef *Test::Harness::Switches; test_harness(0, 'blib/lib', 'blib/arch')" t/*.t
t/00_load.t ................. ok   
t/00_pod.t .................. skipped: Test::Pod 1.00 required for testing POD
t/01_utf8.t ................. ok   
t/02_error.t ................ ok     
t/03_types.t ................ ok     
t/06_pc_pretty.t ............ ok   
t/07_pc_esc.t ............... ok     
t/08_pc_base.t .............. ok     
t/09_pc_extra_number.t ...... ok   
t/10_pc_keysort.t ........... ok   
t/11_pc_expo.t .............. ok   
t/12_blessed.t .............. ok     
t/13_limit.t ................ ok     
t/14_latin1.t ............... ok   
t/15_prefix.t ............... ok   
t/16_tied.t ................. ok   
t/17_relaxed.t .............. ok   
t/18_json_checker.t ......... ok     
t/19_incr.t ................. ok       
t/20_unknown.t .............. ok     
t/21_evans_bugrep.t ......... ok   
t/22_comment_at_eof.t ....... ok     
t/99_binary.t ............... ok         
t/e00_func.t ................ ok   
t/e01_property.t ............ ok     
t/e02_bool.t ................ ok   
t/e03_bool2.t ............... ok     
t/e04_sortby.t .............. ok   
t/e05_esc_slash.t ........... ok   
t/e06_allow_barekey.t ....... ok   
t/e07_allow_singlequote.t ... ok   
t/e08_decode.t .............. ok   
t/e09_encode.t .............. ok   
t/e10_bignum.t .............. ok   
t/e11_conv_blessed_univ.t ... ok   
t/e12_upgrade.t ............. ok   
t/e13_overloaded_eq.t ....... ok   
t/e14_decode_prefix.t ....... ok   
t/e15_tie_ixhash.t .......... ok   
t/e16_incr_parse_fixed.t .... ok   
t/e90_misc.t ................ ok   
t/x00_load.t ................ ok   
t/x02_error.t ............... ok     
t/x12_blessed.t ............. ok     
t/x16_tied.t ................ ok   
t/x17_strange_overload.t .... ok   
t/xe01_property.t ........... ok     
t/xe02_bool.t ............... ok   
t/xe03_bool2.t .............. ok     
t/xe04support_by_pp.t ....... ok   
t/xe05_indent_length.t ...... ok   
t/xe08_decode.t ............. ok   
t/xe10_bignum.t ............. ok   
t/xe11_conv_blessed_univ.t .. ok   
t/xe12_boolean.t ............ ok   
t/xe19_xs_and_suportbypp.t .. ok   
t/xe20_croak_message.t ...... ok   
t/xe21_is_pp.t .............. ok   
All tests successful.
Files=58, Tests=3801,  4 wallclock secs ( 0.45 usr  0.09 sys +  3.01 cusr  0.25 csys =  3.80 CPU)
Result: PASS
  MAKAMAKA/JSON-2.90.tar.gz
  /usr/bin/make test -- OK
Running make install
Appending installation info to /home/eellis/perl5/lib/perl5/x86_64-linux/perllocal.pod
  MAKAMAKA/JSON-2.90.tar.gz
  /usr/bin/make install  -- OK
eellis@eellis-ws ~ $ perl -e "use warnings; use JSON"
Can't locate JSON.pm in @INC (you may need to install the JSON module) (@INC contains: /home/eellis/perl5/perlbrew/perls/perl-5.20.2/lib/site_perl/5.20.2/x86_64-linux /home/eellis/perl5/perlbrew/perls/perl-5.20.2/lib/site_perl/5.20.2 /home/eellis/perl5/perlbrew/perls/perl-5.20.2/lib/5.20.2/x86_64-linux /home/eellis/perl5/perlbrew/perls/perl-5.20.2/lib/5.20.2 .) at -e line 1.
BEGIN failed--compilation aborted at -e line 1.
eellis@eellis-ws ~ $