[ome-devel] XML::LibXML and Later Versions of libxml2

[Chris Allan]

Hello all,

Over the past couple of days I've been fighting with some OME install  
problems that have come down to XML parsing errors. First, some  
background:

callan at valewalker OME $ equery list libxml2
[ Searching for package 'libxml2' in all categories among: ]
* installed packages
[I--] [  ] dev-libs/libxml2-2.6.23 (2)

Our good friend Christian Glahn (phish) who wrote much of the  
XML::LibXML Perl module has not released a new version in over 2  
years. Normally this wouldn't be a problem, however libxml2  
development has happily moved forward (http://xmlsoft.org/news.html)  
since the 1.58 release of XML::LibXML on the 4th April of 2004. In  
fact, there have been no less than 15 libxml2 releases since then (my  
Gentoo libxml2-2.6.23 being based on the 14th).

Now, since XML::LibXML provides Perl bindings to the libxml2 C  
library using Swig and Perl XS, libxml2 API changes can affect things  
in weird and wonderful ways such as "Bad file descriptors" errors  
when attempting to load certain OME XML files during an OME install.  
Less than pleasant, less than descriptive and a little bit arcane.  
However, there is a solution...

Through the power of CVS tree hunting and pecking (http://axkit.org/ 
cgi-bin/viewcvs.cgi/XML-LibXML/ and http://axkit.org/cvs.xml for  
those interested) I've now got a working install using a CVS version  
of XML::LibXML. Checkout here: http://users.openmicroscopy.org.uk/ 
~callan/XML-LibXML-20060512.tar.bz2

If you've got later versions of libxml2 and are having general XML  
parsing weirdness, might want to give an install of that a try.

Ciao.

-Chris