comment on

NOTE: I'm no longer looking for an answer to this specific question, because I'm using plenv instead. However, I would still like to know whether (and why) CPAN checks the versions of modules installed on @INC, when it should just be managing its own directory of modules.

Many modules fail when I try to install them in CPAN, including CPAN itself. This may be because my CPAN thinks it has lower versions of many modules. For example,

cpan[12]> upgrade JSON::PP

Package namespace         installed    latest  in CPAN file
JSON::PP                    2.24000   2.27300  MAKAMAKA/JSON-PP-2.2730
+0.tar.gz
Running install for module 'JSON::PP'
Running make for M/MA/MAKAMAKA/JSON-PP-2.27300.tar.gz
  Has already been unwrapped into directory /home/me/.cpan/build/JSON-
+PP-2.27300-dwlFCV
  Has already been made
Running make test
  Has already been tested successfully
Running make install
  Already done

cpan[13]> r JSON::PP

Package namespace         installed    latest  in CPAN file
JSON::PP                    2.24000   2.27300  MAKAMAKA/JSON-PP-2.2730
+0.tar.gz

cpan[14]> quit
Lockfile removed.
]$ rm -rf ~/.cpan/build/JSON-PP-2.27300-dwlFCV
]$ rm -rf ~/perl5/lib/perl5/JSON
]$ rm -rf ~/.cpan/sources/authors/id/M/MA/MAKAMAKA
]$ cpan

cpan[1]> r JSON::PP
CPAN: Storable loaded ok (v2.20)
Going to read '/home/me/.cpan/Metadata'
  Database was generated on Fri, 29 May 2015 14:17:02 GMT

Package namespace         installed    latest  in CPAN file
JSON::PP                    2.24000   2.27300  MAKAMAKA/JSON-PP-2.2730
+0.tar.gz

cpan[2]> force install JSON::PP

...

Result: PASS
  MAKAMAKA/JSON-PP-2.27300.tar.gz
  /usr/bin/make test -- OK
Running make install
Prepending /home/me/.cpan/build/JSON-PP-2.27300-ZHQLK0/blib/arch /home
+/me/.cpan/build/JSON-PP-2.27300-ZHQLK0/blib/lib to PERL5LIB for 'inst
+all'
Manifying blib/man1/json_pp.1
Appending installation info to /home/me/perl5/lib/perl5/x86_64-linux-t
+hread-multi/perllocal.pod
Installing /home/me/perl5/lib/perl5/JSON/PP.pm
Installing /home/me/perl5/lib/perl5/JSON/PP/Boolean.pm
  MAKAMAKA/JSON-PP-2.27300.tar.gz
  /usr/bin/make install -j17 -- OK

cpan[2]> r JSON::PP

Package namespace         installed    latest  in CPAN file
JSON::PP                    2.24000   2.27300  MAKAMAKA/JSON-PP-2.2730
+0.tar.gz
[download]

Why does it keep reporting version 2.24, even after I've removed the module and after I've installed 2.273 again?

In reply to CPAN frequently reports older module version by philgoetz

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