The TRACE() macro is very like warn $fred, $bill, $!;, except that printing the names of the variables doesn't happen. Package globals do have names that are kept in the symbol table, but not lexicals. You can fiddle with symrefs if you must have the names, but that is a bad habit. Better to just give them explicitly as string arguments to warn

$ perl -e 'my $foo="bar"; warn q/$foo is /, $foo, $!'
$foo is bar at -e line 1.
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The __FILE__ and __LINE__ handling is done by $! warn.

I've been playing with the -D flag to perl, which requires a debugging build. You can get lots of very explicit info about a program that way, but maybe more than you are asking for.

After Compline,
Zaxo