perl >= 5.27 compatibility (cwd in @INC)

gen_ladder.pl

@@ -1,6 +1,9 @@
 #!/usr/bin/perl -w
 use strict;
 
+BEGIN {
+	push @INC, '.';
+}
 use OsmoLadder;
 
 # Script to generate Graphviz (.dot) based ladder diagrams for network