djh has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying to use HTML::HTML5::Parser to parse some HTML pages I stored in files. My program seems to work just fine except with one file and I'm baffled as to what's happening. My program sits in a loop processing files from a list. I've added debugging so it prints the name of the file and then a dump of the document as parsed and then it goes on to process the document except in this one case. So the relevant bit of code is:

for my $filename (@files) { print "$BASE_DIR$filename\n"; #next if $filename eq '2020-02-17-00:10:01.html'; my $doc = $parser->parse_file($BASE_DIR . $filename); print "doc=", Dumper($doc), $doc->toString;

and the output for the problematic file is:

{my home directory}/met-office-datahub/met-office-forecasts/2020-02-17 +-00:10:01.html doc=$VAR1 = bless( do{\(my $o = '93912432739248')}, 'XML::LibXML::Docu +ment' ); <?xml version="1.0" encoding="windows-1252"?> <html xmlns=""><head/><body/></html> Can't call method "toString" on an undefined value ...

Now I've checked the contents of that file and it actually starts (just like all the others):

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"/> <meta http-equiv="X-UA-Compatible" content="IE=Edge">

I can't figure out where that strange alleged file contents is coming from or why it affects just that file. In particular the weird <head/> and <body/> tags. I've searched for those strings in my home directory and in /usr/lib/perl5 and done a web search but haven't found anything.

So I'd be very grateful if anybody has any ideas on techniques to figure out what the problem is, or happens to recognize it :)