Based on https://anonscm.debian.org/viewvc/pkg-java/trunk/libxerces2-java/debian/patches/03_bootclasspath.patch?revision=14509, adopted for guix

--- xerces-2_11_0/build.xml.orig	2010-11-26 21:42:11.000000000 +0100
+++ xerces-2_11_0/build.xml	2017-03-28 14:04:41.946606996 +0200
@@ -290,13 +290,14 @@
            destdir="${build.dest}"
            source="${javac.source}"
            target="${javac.target}"
-           classpath="${build.dir}/classes:${tools.dir}/${jar.apis}:${tools.dir}/${jar.resolver}:${tools.dir}/${jar.serializer}"
+           classpath="${build.dir}/classes:${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
            debug="${debug}" nowarn="true"
            debuglevel="${debuglevel}"
            deprecation="${deprecation}"
            optimize="${optimize}"
            includeAntRuntime="false"
-           includeJavaRuntime="false"
+           includeJavaRuntime="true"
+           bootclasspath="${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
            excludes="org/xml/sax/** 
                 javax/xml/**
                 org/w3c/dom/*
@@ -1451,13 +1452,14 @@
                destdir="${build.dest}"
                source="${javac.source}"
                target="${javac.target}"
-               classpath="${build.dir}/classes:${tools.dir}/${jar.apis}:${tools.dir}/${jar.resolver}:${tools.dir}/${jar.serializer}"
+               classpath="${build.dir}/classes:${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
                debug="${debug}"
                debuglevel="${debuglevel}"
                deprecation="${deprecation}"
                optimize="${optimize}"
                includeAntRuntime="false"
-               includeJavaRuntime="false"
+               includeJavaRuntime="true"
+               bootclasspath="${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
                excludes="org/xml/sax/** 
                     javax/xml/**
                     org/w3c/dom/*
 type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=0ee0dfcc4a576ff9536c979d50a4ec2223b3a3fd'>root</a>/<a href='/guix/log/gnu?id=0ee0dfcc4a576ff9536c979d50a4ec2223b3a3fd'>gnu</a>/<a href='/guix/log/gnu/system?id=0ee0dfcc4a576ff9536c979d50a4ec2223b3a3fd'>system</a>/<a href='/guix/log/gnu/system/accounts.scm?id=0ee0dfcc4a576ff9536c979d50a4ec2223b3a3fd'>accounts.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/system/accounts.scm?id=0ee0dfcc4a576ff9536c979d50a4ec2223b3a3fd&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-03-25 23:37:06 +0100'>2019-03-25</span></td><td><a href='/guix/commit/gnu/system/accounts.scm?id=cf848cc0a17a3a58d600116896f6e7abfb0440d4'>accounts: Add default value for the 'home-directory' field of &lt;user-account&gt;.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/accounts.scm (&lt;user-account&gt;)[home-directory]: Mark as
thunked and add a default value.
(default-home-directory): New procedure.
* doc/guix.texi (User Accounts): Remove 'home-directory' from example.
* gnu/system/examples/bare-bones.tmpl: Likewise.
* gnu/system/examples/beaglebone-black.tmpl: Likewise.
* gnu/system/examples/desktop.tmpl: Likewise.
* gnu/system/examples/docker-image.tmpl: Likewise.
* gnu/system/examples/lightweight-desktop.tmpl: Likewise.
* gnu/system/install.scm (installation-os): Likewise.
* gnu/tests.scm (%simple-os): Likewise.
* gnu/tests/install.scm (%minimal-os, %minimal-os-on-vda):
(%separate-home-os, %encrypted-root-os, %btrfs-root-os): Likewise.
* tests/accounts.scm ("allocate-passwd")
("allocate-passwd with previous state"): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-03-07 20:05:09 +0100'>2019-03-07</span></td><td><a href='/guix/commit/gnu/system/accounts.scm?id=6061d01512081c93c53fdd1d4302b36696403061'>activation: Operate on &lt;user-account&gt; and &lt;user-group&gt; records.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/accounts.scm (sexp-&gt;user-group, sexp-&gt;user-account): New
procedures.
* gnu/system/shadow.scm (account-activation): Call them in the arguments
to 'activate-users+groups'.
(account-shepherd-service): Likewise.
* gnu/build/activation.scm (activate-users+groups): Expect a list of
&lt;user-account&gt; and a list of &lt;user-group&gt;.  Replace uses of 'match' on
tuples with calls to record accessors.
(activate-user-home): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-03-07 20:04:02 +0100'>2019-03-07</span></td><td><a href='/guix/commit/gnu/system/accounts.scm?id=f6f67b87c08fe7b901db834c714aceaef2b62b60'>system: Add (gnu system accounts).</a><span class='msg-avail'>...<span class='msg-tooltip'>The (gnu system accounts) module is meant to be used both on the build-
and on the host-side.

* gnu/system/shadow.scm &lt;top level&gt;: Call 'default-shell'.
(&lt;user-account&gt;, &lt;user-group&gt;): Move to...
* gnu/system/accounts.scm: ... here.  New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add system/accounts.scm.
</span></span></td><td>Ludovic Courtès</td></tr>