Hmm ... ok.

For File::Temp v0.2304, all tests pass. (It's possible I might have encountered the problem if I had tried to build perl myself.) In t/from_file.t, of F::Next, use of F::Temp seems simple enough ...

FROM_OK_FILE_BUT_MISSING: {
    my $warn_called;
    local $SIG{__WARN__} = sub { $warn_called = 1 };
 
    my $tempfile = File::Temp->new;
    File::Copy::copy('t/filelist.txt', $tempfile);
    print {$tempfile} "t/non-existent-file.txt\n";
    $tempfile->close;
    ...
}
[download]

... nothing odd is there about File::Temp->new().

Oh, odd thing is of course use of MS Windows. I suppose. :-| (I wonder if newer versions for F::{Next,Temp} would make any difference.)