Please copy and paste the code you're actually running, this does not run:

Global symbol "@uut_name" requires explicit package name at derp.pl li
+ne 15.
Global symbol "@enable_nets" requires explicit package name at derp.pl
+ line 16.
Execution of derp.pl aborted due to compilation errors.
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Update: You say you're successfully writing something to a file, the code you've posted doesn't do this the way you expect. For clarity, show us what you expect the output to be. Also use the three argument open, and report the reason for failures as documented in open. How do I post a question effectively? has tips on asking for help.