Beginning of better docs for --self-contained courtesy of markstos@cpan.org.

[p5sagit/local-lib.git] / lib / local / lib.pm

diff --git a/lib/local/lib.pm b/lib/local/lib.pm
index 6b1f5f9..1dd92a7 100644 (file)
--- a/lib/local/lib.pm
+++ b/lib/local/lib.pm
@@ -11,7 +11,7 @@ use File::Path ();
 use Carp ();
 use Config;
 
-our $VERSION = '1.004008'; # 1.4.7
+our $VERSION = '1.005000'; # 1.5.0
 my @KNOWN_FLAGS = (qw/--self-contained/);
 
 sub import {
@@ -21,7 +21,7 @@ Please see `perldoc local::lib` for directions on using this module.
 DEATH
 
   # Remember what PERL5LIB was when we started
-  my $perl5lib = $ENV{PERL5LIB};
+  my $perl5lib = $ENV{PERL5LIB} || '';
 
   my %arg_store;
   for my $arg (@args) {
@@ -157,11 +157,7 @@ sub resolve_home_path {
   my ($user) = ($path =~ /^~([^\/]+)/); # can assume ^~ so undef for 'us'
   my $tried_file_homedir;
   my $homedir = do {
-    if (
-        eval { require File::HomeDir }
-        # Use CPAN::Version if available as it deals correctly with dev releases
-        && (eval { require CPAN::Version; } ? CPAN::Version->vgt($File::HomeDir::VERSION, 0.65) : $File::HomeDir::VERSION >= 0.65
-    )) {
+    if (eval { require File::HomeDir } && $File::HomeDir::VERSION >= 0.65) {
       $tried_file_homedir = 1;
       if (defined $user) {
         File::HomeDir->users_home($user);
@@ -571,6 +567,26 @@ PATH is appended to, rather than clobbered.
 
 These values are then available for reference by any code after import.
 
+=head1 CREATING A SELF-CONTAINED SET OF MODULES
+
+You can use local::lib to prepare a directory which contains a module and all
+of its non-core dependencies.  The C<--self-contained> option ignores any
+globally installed modules when resolving dependencies, only considering
+modules installed in a "local::lib" directory or provided by core Perl.
+
+A use-case for this feature would be to prepare to deploy a whole "stack" of
+module dependencies on a new machine, even if you have copies of the same
+dependencies installed globally already.
+
+The C<--self-contained> option should be used like this: 
+
+  # Install LWP and *all non-core* dependencies to the 'my_lwp' directory 
+  perl -MCPAN -Mlocal::lib=--self-contained,my_lwp -e 'CPAN::install(LWP)'
+
+Note that some dependencies may involve C-based "XS" code even if your target
+module doesn't. The issue of dealing with XS vs Pure Perl code is beyond the scope
+of what local::lib provides. 
+
 =head1 METHODS
 
 =head2 ensure_directory_structure_for