Yep, this works on Linux: 
#!/usr/bin/perl
use warnings;
use strict;

use Tk;
use Proc::Background;

my $mw     = MainWindow->new;
my $msg    = $mw->Label(-text => 'Press the button once ready.')->pack
+;

my $button = $mw->Button(-text    => 'Start',
                         -command => \&run,
                        )->pack;

MainLoop();

sub run {
    my $proc = Proc::Background->new('kate'); # an editor
    $mw->update while $proc->alive;
    $mw->Label(-text => 'Finished.')->pack;
    $button->destroy;
}

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لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^2: Perl/Tk window contents disappear when obscured then revealed by choroba
in thread Perl/Tk window contents disappear when obscured then revealed by Another Ed

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