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/*
 value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=54bee9ea2eee1bd93657f6817bf7cc7aed3b18a6'>root</a>/<a href='/guix/log/gnu?id=54bee9ea2eee1bd93657f6817bf7cc7aed3b18a6'>gnu</a>/<a href='/guix/log/gnu/packages?id=54bee9ea2eee1bd93657f6817bf7cc7aed3b18a6'>packages</a>/<a href='/guix/log/gnu/packages/pcre.scm?id=54bee9ea2eee1bd93657f6817bf7cc7aed3b18a6'>pcre.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/packages/pcre.scm?id=54bee9ea2eee1bd93657f6817bf7cc7aed3b18a6&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-07-22 17:54:54 +0200'>2018-07-22</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=08b87ab0dfa4bae0eb57f3d8915f655bf20d94fc'>gnu: pcre: Update to 8.42.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-07-19 00:53:10 +0200'>2018-07-19</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=50849734e986a5824bcca20fe64b2886f8f1a42b'>gnu: pcre: Install static libraries to separate output.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-02-28 18:23:31 +0100'>2018-02-28</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=8297ff0f931a677c51ca7c64a844a55cd6cd2ef4'>gnu: pcre2: Update to 10.31.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2018-01-19 23:59:20 -0500'>2018-01-19</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=e074a655dd6497daafbd62737e3b63f3d5aa7985'>Merge branch 'master' into core-updates</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2018-01-13 21:25:40 +0100'>2018-01-13</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=265c31f5a377851eb583dfeaaaae6132e085cfac'>gnu: pcre: Use HTTPS for home pages.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-10-01 22:16:41 +0300'>2017-10-01</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=0b7f9806dbde1a7c1ded4218e499319d7eafbe7a'>gnu: pcre: Update to 8.41.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2017-07-23 03:42:12 -0400'>2017-07-23</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=6c1a317e29c45e85e3a0e050612cdefe470b100c'>Merge branch 'master' into core-updates</a></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-07-20 08:26:40 -0400'>2017-07-20</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=426b0b898f70a58133d80779980f163a5761686e'>gnu: pcre: Update replacement to 8.41 [fixes CVE-2017-{7244,7245,7246}].</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-07-03 23:51:22 +0200'>2017-07-03</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=d5ec5ed7197d121130af6953378bcfd8929a9754'>packages: Mark 'replacement' as an "innate" field.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-05-24 12:05:47 +0200'>2017-05-24</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=d1a914082b7e53636f9801769ef96218b2125c4b'>Merge branch 'master' into core-updates</a></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2017-05-07 17:46:00 -0400'>2017-05-07</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=af6e2385b3125924f34188d81370dd71cdbe9ddc'>gnu: pcre2: Fix build configuration for pcre2.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-05-07 17:46:00 -0400'>2017-05-07</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=37f46a4bc51886c0d0df797bfbb13a50fe647567'>gnu: pcre2: Fix CVE-2017-8786.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>