your package libapache-mod-jk is provding an Apache2 web server module.
We're upgrading Apache to the new upstream version 2.4  (tracked
as transition bug #661958). This requires all modules to be rebuilt
due to ABI changes. Thus, you need to rebuild and reupload your
Apache2 module package in a version compatible to our new package
available in experimental . Please note it is not enough to
simply rebuild the module - it needs some adaptions in the module
package metadata. We have written packaging guidelines for our
reverse dependencies . Please read it carefully, it should be able
to answer most of your questions. Do also look at dh_apache2
(available through the dh-apache2 package) which can simplify
packaging Apache2 modules. In short, we want to highlight these
changes you need to be aware of.
* APIs changed for some cases . Chances are your module needs some
adaptions, please get in touch with upstream or us if you need help
to port your module to Apache 2.4.
* MPM packages are gone. You cannot depend or conflict with a
particular MPM anymore. If your module does not work with a
particular module, make sure to make it abort with an error if
loaded together with an incompatible MPM. You can use our
apache2-maintscript-helper  to switch to the MPM of your choice
in your maintainer scripts.
* Do not build-depend on apache2-threaded-dev or apache2-prefork-dev
anymore. Just like MPMs are gone, are our MPM -dev packages as
well. All modules need to simply build-depend on apache2-dev.
* Do NOT depend on apache2, apache2-common or any other real apache2
package in your binary module package. Depend on our virtual
apache2-api-20120211 package only!
* Do NOT call a2enmod/a2dismod in your maintainer scripts. Use our
apache2-maintscript-helper  instead. This is required to get a
uniform and stateful handling of all Apache2 modules.
You can look at our Apache 2.4 packaging hints  for hands-on
tutorials. Please note: This bug is filed as "important" for now. As
the time goes by we plan make it a release critical severity. In the
consequences your module either needs an update or is going to be
removed from Wheezy. For the time being please tag the bug as pending
as soon as you have a package ready. We strongly recommend that at
least maintainers of complex module packages make an upload to
experimental as well. Of course, uploading simple modules to
experimental is welcome, too.
This is the maintainer address of Debian's Java team
debian-j...@lists.debian.org for discussions and questions.