Unload modules before rechecking version after installation

install-deps.pl

@@ -11,9 +11,15 @@
 
 sub is_installed
 {
-   my ( $mod, $want_ver ) = @_;
+   my ( $mod, $want_ver, %opts ) = @_;
 
    ( my $modfile = "$mod.pm" ) =~ s{::}{/}g;
+
+   if( $opts{unload_first} ) {
+      # unload the module in case we already loaded an older version
+      delete $INC{$modfile};
+   }
+
    return 0 unless( eval { require $modfile; 1 } );
 
    defined $want_ver or return 1;
@@ -40,7 +46,7 @@ sub requires
       # cpan returns zero even if installation fails, so we double-check
       # that the module is installed after running it.
       system( $^X, "-MCPAN", "-e", qq(install "$mod") ) == 0 and
-         is_installed( $mod, $ver ) and
+         is_installed( $mod, $ver, unload_first => 1 ) and
          return;
 
       print STDERR "Failed to install $mod\n";