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/*
td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=e2227b6adae0abdb9aa5b9995ccf89d38b2314d7'>root</a>/<a href='/guix/log/gnu?id=e2227b6adae0abdb9aa5b9995ccf89d38b2314d7'>gnu</a>/<a href='/guix/log/gnu/installer.scm?id=e2227b6adae0abdb9aa5b9995ccf89d38b2314d7'>installer.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/installer.scm?id=e2227b6adae0abdb9aa5b9995ccf89d38b2314d7&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-01-17 14:04:26 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=5737ba841bd8e21e1cb5dc63e1fc5e09d31482bb'>installer: Various renamings.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:26 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=bf304dbceadf89c2722168be97d9673f94608aa6'>installer: partionment: Add encryption support.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:25 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=133c401f774d803f92933e9cadb6791641913beb'>installer: Display an eventual backtrace in a page.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:24 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=5bfdde503e0ce3b6518a247e01082848a23aa056'>installer: Reorder partitionment step.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:24 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=69a934f23ae1bd7dda9ec269a6ce3012e13c9011'>installer: Add partitioning support.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:23 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=6efd8430aeaa5b062a95202b9458435738ae2930'>installer: Fix comments.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:23 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=b4658c258eaf7731dbb45409aedef58afc5de93a'>installer: Add hostname.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:23 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=b51bde71a9385f4e81fbea258bfb9e8ff48be119'>installer: Add services page.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:23 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=c088b2e47f6675199f1ef545df7d04d4532e64e3'>installer: Do not ask for keyboard model.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:22 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=dc5f3275ecbddc804875899e9e457299a835d7ab'>installer: Add configuration formatter.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:21 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=6b48825e4ba6435c2e3bbc85857ade16552be9c3'>installer: Fix locale installation.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:21 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=a49d633c0c65975263270f5ac0050482ca6a5513'>installer: Move everything to the build side.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-01-17 14:04:20 +0100'>2019-01-17</span></td><td><a href='/guix/commit/gnu/installer.scm?id=d0f3a672dcbdfefd3556b6a21985ff0e35eed3be'>gnu: Add graphical installer support.</a><span class='msg-avail'>...</span></td><td>Mathieu Othacehe</td></tr>