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/*
></table>
<div class='path'>path: <a href='/guix/log/?id=81a24d3050b0f2b221e5cc5756fc26f4cdf1876c'>root</a>/<a href='/guix/log/gnu?id=81a24d3050b0f2b221e5cc5756fc26f4cdf1876c'>gnu</a>/<a href='/guix/log/gnu/packages.scm?id=81a24d3050b0f2b221e5cc5756fc26f4cdf1876c'>packages.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.scm?id=81a24d3050b0f2b221e5cc5756fc26f4cdf1876c&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-12-12 23:23:33 +0100'>2024-12-12</span></td><td><a href='/guix/commit/gnu/packages.scm?id=97e7e47d6f1e036e1ed6bd3f428e40d9794a3353'>packages: Optimize ‘all-packages’.</a><span class='msg-avail'>...<span class='msg-tooltip'>On my laptop, wall-clock time for (all-packages) goes from 27s to 1s.

* gnu/packages.scm (all-packages): Use a hash table to remember visited
packages instead of calling ‘delete-duplicates’ on the final list.

Change-Id: I4aae804656b56ef2095993e91f0572a5891f419f
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2024-12-01 20:14:15 +0100'>2024-12-01</span></td><td><a href='/guix/commit/gnu/packages.scm?id=4b5dae8defe4c0d5e98b5ce6abba853007485f23'>packages: Factorize ‘all-packages’.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages.scm (all-packages): New procedure.
* etc/source-manifest.scm (all-packages): Remove.
* guix/scripts/graph.scm (all-packages): Remove.
* guix/scripts/refresh.scm (all-packages): Remove.
* guix/scripts/weather.scm (all-packages): Remove.

Change-Id: I6072952c4b877b541037ce86402cfb7744eeb0a0
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-01-25 18:14:42 +0100'>2023-01-25</span></td><td><a href='/guix/commit/gnu/packages.scm?id=8b2721de6af76780611fe9f86fa5d4cd062400d1'>packages: Adjust 'generate-package-cache' for Guile 3.0.9.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages.scm (generate-package-cache): Adjust for Guile 3.0.9.
</span></span></td><td>Ludovic Courtès</td></tr>