[perl-gtk2-trayicon] Makefile.PL: added META_MERGE block with 'configure_requires'

[Brian Manning <bmanning src gnome org>]

commit 2f0663bba272873e0df741ba9dd9b69096476d51
Author: Brian Manning <bmanning src gnome org>
Date:   Tue Oct 20 13:42:28 2020 -0700

    Makefile.PL: added META_MERGE block with 'configure_requires'
    
    - This fixes RT#129462
    - Added a '%pre_reqs' hash with build prereqs for use in various places

 Makefile.PL | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)
---
diff --git a/Makefile.PL b/Makefile.PL
index 1f05740..63a509a 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -15,6 +15,13 @@ our %build_reqs = (
        'perl-Gtk2'               => '1.00',
 );
 
+our %pre_reqs = (
+    'Glib'                => $build_reqs{'perl-Glib'},
+    'Gtk2'                => $build_reqs{'perl-Gtk2'},
+    'ExtUtils::Depends'   => $build_reqs{'perl-ExtUtils-Depends'},
+    'ExtUtils::PkgConfig' => $build_reqs{'perl-ExtUtils-PkgConfig'},
+);
+
 # Writing a fake Makefile ensures that CPAN will pick up the correct
 # dependencies and install them.
 unless (eval "use ExtUtils::Depends;"
@@ -29,12 +36,7 @@ unless (eval "use ExtUtils::Depends;"
    warn "$@\n";
    WriteMakefile(
          PREREQ_FATAL => 1,
-         PREREQ_PM    => {
-            Glib::                => $build_reqs{'perl-Glib'},
-            Gtk2::                => $build_reqs{'perl-Gtk2'},
-            ExtUtils::Depends::   => $build_reqs{'perl-ExtUtils-Depends'},
-            ExtUtils::PkgConfig:: => $build_reqs{'perl-ExtUtils-PkgConfig'},
-         },
+         PREREQ_PM    => \%pre_reqs,
    );
    exit 1; # not reached
 }
@@ -66,8 +68,8 @@ WriteMakefile(
     ABSTRACT_FROM   => 'TrayIcon.pm', # retrieve abstract from module
     XSPROTOARG      => '-noprototypes',
     $trayicon->get_makefile_vars,
-    PREREQ_PM       =>  {
-       Gtk2 => 0.96,
+    META_MERGE    => {
+       configure_requires => \%pre_reqs,
     },
 );