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/*

Don't unzip the sources which were bundled originally. Guix strips them from

the source and uses pre-build packages.

Taken from https://anonscm.debian.org/viewvc/pkg-java/trunk/libxerces2-java/debian/patches/02_build_dont_unzip.patch?revision=14507

Index: b/build.xml

===================================================================

--- a/build.xml

+++ b/build.xml

@@ -247,7 +247,7 @@

     <copy file="${src.dir}/org/apache/xerces/impl/xpath/regex/message.properties"

       tofile="${build.src}/org/apache/xerces/impl/xpath/regex/message_en.properties"/>

-    <!-- now deal with API's:  -->

+    <!-- not needed for Debian

     <unzip src="${src.apis.zip}" dest="${build.src}">

         <patternset

             includes="org/xml/sax/** 

@@ -270,6 +270,7 @@

                 org/w3c/dom/xpath/**"

         />

     </unzip>

+    -->

     <!-- substitute tokens as needed -->

     <replace file="${build.dir}/src/org/apache/xerces/impl/Version.java" 

@@ -1232,7 +1233,7 @@

     <replace file="${build.dir}/src/org/apache/xerces/parsers/AbstractSAXParser.java"

              token="return (fConfiguration instanceof XML11Configurable);" value="return false;"/>

-    <!-- now deal with API's:  -->

+    <!-- not needed for Debian

     <unzip src="${src.apis.zip}" dest="${build.src}">

         <patternset

             includes="org/xml/sax/** 

@@ -1255,7 +1256,7 @@

                 org/w3c/dom/xpath/**"

         />

     </unzip>

-

+    -->

     <!-- substitute tokens as needed -->

     <replace file="${build.dir}/src/org/apache/xerces/impl/Version.java" 

Index: b/src/manifest.xerces

===================================================================

--- a/src/manifest.xerces

+++ b/src/manifest.xerces

@@ -1,5 +1,6 @@

 Manifest-Version: 1.0

 Created-By: @java.version@ (@java.vendor@)

+Class-Path: xml-apis-ext.jar xml-resolver.jar jaxp-1.4.jar

 Name: org/apache/xerces/impl/Version.class

 Comment: @impl.name@ 

This patch eliminates the need for providing "xjavac", which saves building a

package for the unmaintained "xerces-tools".

Taken from https://anonscm.debian.org/viewvc/pkg-java/trunk/libxerces2-java/debian/patches/01_xjavac_taskdef.patch?revision=14507

Index: b/build.xml

===================================================================

--- a/build.xml

+++ b/build.xml

@@ -39,7 +39,7 @@

   <property name="tools.dir" value="./tools"/>

   <!-- enable compilation under JDK 1.4 and above -->

-  <taskdef name="xjavac" classname="org.apache.xerces.util.XJavac">

+  <taskdef name="xjavac" classname="org.apache.tools.ant.taskdefs.Javac">

     <classpath>

       <pathelement location="${tools.dir}/bin/xjavac.jar"/>

     </classpath>

@@ -291,7 +291,7 @@

            source="${javac.source}"

            target="${javac.target}"

            classpath="${build.dir}/classes:${tools.dir}/${jar.apis}:${tools.dir}/${jar.resolver}:${tools.dir}/${jar.serializer}"

-           debug="${debug}"

+           debug="${debug}" nowarn="true"

            debuglevel="${debuglevel}"

            deprecation="${deprecation}"

            optimize="${optimize}"

@@ -359,7 +359,7 @@

            source="${javac.source}"

            target="${javac.target}"

            classpath="${build.dir}/classes:${tools.dir}/${jar.apis}"

-           debug="${debug}"

+           debug="${debug}" nowarn="true"

            debuglevel="${debuglevel}"

            includeAntRuntime="false"

            includeJavaRuntime="true"/>

@@ -379,7 +379,7 @@

            source="${javac.source}"

            target="${javac.target}"

            classpath="${tools.dir}/${jar.apis}:${build.dir}/classes:./tools/junit.jar"

-           debug="${debug}"

+           debug="${debug}" nowarn="true"

            debuglevel="${debuglevel}"

            includeAntRuntime="false"

            includeJavaRuntime="true"/>