Bug#1093338: libbio-eutilities-perl: FTBFS: Failed 8/20 test programs. 0/174 subtests failed.

[gregor herrmann]

On Thu, 23 Jan 2025 23:46:51 +0000, David Miguel Susano Pinto wrote:

> 2. A Debian packaging bug?
> 
>    After installing all these Debian packages, the default XML parser
>    ends up being XML::SAX::PurePerl.  It shouldn't.  The default
>    behaviour of XML::SAX is to use the latest installed.  Since the
>    PurePerl parser comes with XML::SAX itself, it should be the first to
>    be installed and therefore only used when no other is available.
> 
>    I'm not sure how XML::SAX knows which parser was last installed but
>    this seems like a Debian package issue to me.

Thanks for looking into this!

I got curious and had a brief look:
There's update-perl-sax-parsers in libxml-sax-perl which handles the
various parsers:
https://salsa.debian.org/perl-team/modules/packages/libxml-sax-perl/-/blob/master/debian/update-perl-sax-parsers?ref_type=heads
(update-perl-sax-parsers gets called by te postinst script in the
various packages.)

And on my laptop this seems to work -- as in it looks like described
in the manpage:
https://manpages.debian.org/unstable/libxml-sax-perl/update-perl-sax-parsers.8.en.html

# ll /var/lib/libxml-sax-perl/ParserDetails.d
total 16
-rw-r--r-- 1 root root  66 Nov 22 13:36 10-XML::SAX::PurePerl
-rw-r--r-- 1 root root  64 Jan 24 13:01 50-XML::LibXML::SAX
-rw-r--r-- 1 root root  72 Jan 24 13:01 50-XML::LibXML::SAX::Parser
-rw-r--r-- 1 root root 181 Dec 11  2022 50-XML::SAX::Expat

So XML::SAX::PurePerl has the lowest priority.

# cat /etc/perl/XML/SAX/ParserDetails.ini
[XML::SAX::PurePerl]
http://xml.org/sax/features/namespaces = 1


[XML::LibXML::SAX]
http://xml.org/sax/features/namespaces = 1


[XML::LibXML::SAX::Parser]
http://xml.org/sax/features/namespaces = 1


[XML::SAX::Expat]
http://xml.org/sax/features/external-general-entities = 1
http://xml.org/sax/features/external-parameter-entities = 1
http://xml.org/sax/features/namespaces = 1


And XML::SAX::PurePerl is mentioned first; and XML::SAX::Expat should
be the one which gets used.
 


So I'm not sure under which circumstances XML::SAX::PurePerl gets
used as the default parser, but maybe this helps other to take a
deeper look.


Cheers,
gregor

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