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" 
es/ceph-skip-unittest_blockdev.patch?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/ceph-skip-unittest_blockdev.patch'>
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<div class='path'>path: <a href='/guix/log/?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3'>root</a>/<a href='/guix/log/gnu?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3'>gnu</a>/<a href='/guix/log/gnu/packages?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3'>patches</a>/<a href='/guix/log/gnu/packages/patches/ceph-skip-unittest_blockdev.patch?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3'>ceph-skip-unittest_blockdev.patch</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/patches/ceph-skip-unittest_blockdev.patch?id=8640f9ec91f7a9e81457a3651a06465fd8dd03a3&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2017-03-28 16:35:37 +0200'>2017-03-28</span></td><td><a href='/guix/commit/gnu/packages/patches/ceph-skip-unittest_blockdev.patch?id=dcfe44cbce97e887d033b6adefd7669f47c36e4f'>gnu: Add ceph.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/storage.scm,
  gnu/packages/patches/ceph-disable-cpu-optimizations.patch,
  gnu/packages/patches/ceph-skip-collect-sys-info-test.patch,
  gnu/packages/patches/ceph-skip-unittest_blockdev.patch: New files.
* gnu/local.mk (GNU_SYSTEM_MODULES, dist_patch_DATA): Register it.
</span></span></td><td>Marius Bakke</td></tr>