[blfs-support] Python module libxml2 needed by itstool? - BLFS 8.2

[r***@gmail.com]

When compiling itstool in BLFS 8.2 I receive:

   checking for Python module libxml2... not found
   configure error: Python module libxml2 is needed to run this package

I'm confused as I don't see the Python module listed as a requirement. 
I see docbook (installed), which requires libxml2 (installed).  However,
that libxml2 doesn't seem to be the Python module of the same name.

But after compiling the libxml2 Python module I still receive the errors
listed above, although the module appeared to compile properly and I see
the Installed Programs listed in Contents.

[Ken Moffat]

Post by r***@gmail.com
   checking for Python module libxml2... not found
   configure error: Python module libxml2 is needed to run this package
I'm confused as I don't see the Python module listed as a requirement.  I
see docbook (installed), which requires libxml2 (installed).  However, that
libxml2 doesn't seem to be the Python module of the same name.
But after compiling the libxml2 Python module I still receive the errors
listed above, although the module appeared to compile properly and I see the
Installed Programs listed in Contents.

I think that what you want is
/usr/lib/python3.6/site-packages/libxml2.py which for me was
installed by libxml2. Possibly also drv_libxml2.py in the same
directory.

If those are what you are referring to in your last sentence, then
please disregard the rest of this email. Trying to grok the names
of Python modules, and where they come from, is often painful (some
of them install several files).

I speak from bitter experience tracking down Shiboken2 last night (it
is still in git, and regarded as experimental by the package which
could use it - so it ain't going into the book except as a link to a
wiki - but it is actually installed by pyside-setup from PySide2
which is separately listed as an experimental dependency by the same
package).

For docbook-related packages (and I group libxml2 amongst those) I
am always reluctant to change things in my build because it is so
easy to break something and not find out until much later (the need
for Python2's corresponding module by gimp-help was the most recent
change where I remember breakage).

So, my build order is:

sgml-common, OpenSP, openjade, docbook31, docbook45, dsssl, SGMLSpm,
docbook-utils, libxml2, python2 version of libxml2 for gimp-help,
libxslt, docbook-xml, docbook-xslt, xmlto.

We build libxml2 with a patch and a sed, both re python, and we
point configure to python3. Maybe you missed one of those items
when you built it, or perhaps one of the items I listed above which
I built before libxml2 might turn out to be needed.

ĸen