I should have taken tilly's suggestion from the VERY
start and used Temp::File. And now I feel quite
foolish, but perhaps a little bit wiser, and I must acknowledge my folly
to the Perlmonks who've endured me.
in reply to More Eyes, Please
Especially since the solution which would solve this mystery
was in none of the pieces of code I posted here. I realized
that the original block of code I posted in the parent thread
was in a subroutine which had been called by ANOTHER subroutine,
and in THAT subroutine I had already opened and flocked a
tempfile which had been created moments ago with the exact
same naming scheme.
So the most obvious solution was invisible to me late at night: "The file exists, and that's why you can't get a lock on it, dumbass!"
Thankfully things were clearer in the morning. I feel sooo silly.