There are two problems there. qw takes each blank characters separated elements in its operand (most often, words separated by spaces) and reads them in a simple quotish context. Put a simpler way, qw(A $b C %h); could also be written ('A', '$b', 'C', '%h'). In Ruby there is a qw-like construct that allows double-quotish interpretation, but this is Perl. So you instead have to write use lib ("$some_path/lib",); (the comma is optional, I just always put an extra comma in a single element list).

The second issue is that use is called straightaway, so you could say that perl reads your program : 

# Compiling
using File::Spec
using File::Basename
there is a global variable called $some_path
add to path $some_path/lib

_Compilation complete_

# Running
$some_path = dirname(File::Spec->rel2abs(__FILE__));

[download]
This is of course really simplified.

The BEGIN keyword means that a block has to be executed during compile time, and not to wait after compilation completion. You should write: 

my $some_path;
BEGIN { 
   $some_path = "/my/path";
}
use lib "$some_path/lib"; # Yeah, you don't even need the parenthesis,
+ Perl is clever enough for you
# Edit : thanks dave_the_m for the correction

[download]

In reply to Re^3: use lib statement with path variable by Eily
in thread use lib statement with path variable by sans-clue

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.