Bug: Error message for `.rab` file open failure references wrong variable (`$netfile` instead of `$rabfile`)

[akutuva21]

Summary

In MacroBNGModel.pm, when opening the .rab output file for writing, the die message incorrectly prints $netfile instead of $rabfile. If the write-open fails, the error will blame the wrong file.

Location

File: bng2/Perl2/MacroBNGModel.pm, line 991

Current behavior

$rabfile = "macr_${param_prefix}.rab";
$netfile = "macr_${param_prefix}.net";
open (RFILEnet, "<", $netfile) or die "Can't open $netfile: $!\n";
open (WFILErab, ">", $rabfile) or die "Can't open $netfile: $!\n";
#                                                  ^^^^^^^^
#                                          Should be $rabfile

If the .rab file can't be opened for writing (e.g., permissions issue), the error message will say:

Can't open macr_foo.net: Permission denied

...when the actual problem is with macr_foo.rab.

Expected behavior

open (WFILErab, ">", $rabfile) or die "Can't open $rabfile: $!\n";

How to verify

sed -n '988,992p' bng2/Perl2/MacroBNGModel.pm

Suggested fix

Change $netfile to $rabfile in the die string on line 991.