setup: rework setup_explicit_git_dir()

diff --git a/git-difftool.perl b/git-difftool.perl
index adc42de8752fd395707f1e395c61991b3146cebb..e95e4ad973f21dd104950dc6ebb28485844b36f4 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -10,6 +10,7 @@
 #
 # Any arguments that are unknown to this script are forwarded to 'git diff'.
 
+use 5.008;
 use strict;
 use warnings;
 use Cwd qw(abs_path);