Now that I have your attention, what I mean is this: 

use 5.6.0;

[download]

The 'use VERSION' syntax only became available in 5.6 -- older versions of Perl won't even compile it to report a proper error about the perl version. Update: ikegami pointed out that 'use VERSION' is older -- only the dotted-numeric part is 5.6 or later.

$ perl555 -e 'use 5.6.0'    
syntax error at -e line 1, near "use 5.6"
Execution of -e aborted due to compilation errors.

[download]

Moreover, it uses the dotted-numeric form that older Perl's don't understand.

$ perl555 -e 'require 5.6.0'
Can't locate 5.60 in @INC (@INC contains ...[snip]...) at -e line 1.

[download]

Instead, use one of these:

require 5.006;            # run-time

BEGIN { require 5.006; }  # compile-time

[download]

These do what you want.

$ perl555 -e 'require 5.006'
Perl 5.006 required--this is only version 5.00505, stopped at -e line 
+1.

[download]

If you're writing modules for others to use (e.g. CPAN), and need a minimum perl version, put a 'require 5.006' (or whatever version you need) at the top of your Makefile.PL or Build.PL. This will die with a useful error message before the Makefile or Build file is created. Moreover, CPAN Testers clients like CPANPLUS and CPAN::Reporter will recognize the error message and file an 'NA' report instead of a 'FAIL' report.

I wonder if there is a Perl::Critic policy about this. If not, there should be.

-xdg

Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

In reply to Don't use 5.6.N by xdg

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.