Allow re-targeting of naclports install

libraries/SDL-1.2.14/nacl-SDL-1.2.14.sh

 #!/bin/bash
 # Copyright (c) 2011 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 # nacl-SDL-1.2.14.sh
 #
 # usage:  nacl-SDL-1.2.14.sh
 #
@@ skipping 10 matching lines @@
 export LIBS=-lnosys
 
 CustomConfigureStep() {
   Banner "Configuring ${PACKAGE_NAME}"
   # export the nacl tools
   export CC=${NACLCC}
   export CXX=${NACLCXX}
   export AR=${NACLAR}
   export RANLIB=${NACLRANLIB}
   export CFLAGS="-I${NACL_SDK_ROOT}/include"
-  export PKG_CONFIG_PATH=${NACL_SDK_USR_LIB}/pkgconfig
-  export PKG_CONFIG_LIBDIR=${NACL_SDK_USR_LIB}
+  export PKG_CONFIG_PATH=${NACLPORTS_LIBDIR}/pkgconfig
+  export PKG_CONFIG_LIBDIR=${NACLPORTS_LIBDIR}
   export PATH=${NACL_BIN_PATH}:${PATH};
   ChangeDir ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}
   ./autogen.sh
 
   # TODO(khim): remove this when nacl-gcc -V doesn't lockup.
   # See: http://code.google.com/p/nativeclient/issues/detail?id=2074
   TemporaryVersionWorkaround
   ChangeDir ${NACL_PACKAGES_REPOSITORY}/${PACKAGE_NAME}
 
   Remove ${PACKAGE_NAME}-build
   MakeDir ${PACKAGE_NAME}-build
   cd ${PACKAGE_NAME}-build
   set -x 
   ../configure \
     --host=nacl \
     --disable-assembly \
     --disable-pthread-sem \
     --disable-shared \
-    --prefix=${NACL_SDK_USR} \
-    --exec-prefix=${NACL_SDK_USR} \
-    --libdir=${NACL_SDK_USR_LIB} \
-    --oldincludedir=${NACL_SDK_USR_INCLUDE}
+    --prefix=${NACLPORTS_PREFIX} \
+    --exec-prefix=${NACLPORTS_PREFIX} \
+    --libdir=${NACLPORTS_LIBDIR} \
+    --oldincludedir=${NACLPORTS_INCLUDE}
   set +x
 }
 
 CustomPackageInstall() {
   DefaultPreInstallStep
   DefaultDownloadStep
   DefaultExtractStep
   DefaultPatchStep
   CustomConfigureStep
   DefaultBuildStep
   DefaultInstallStep
   DefaultCleanUpStep
 }
 
 CustomPackageInstall
 exit 0