Use conventional names for installation directories:
 - DESTDIR instead of BUILD_ROOT
 - PREFIX instead of SBCL_PREFIX and INSTALL_ROOT

--- INSTALL.orig	2011-12-06 11:17:02.000000000 +0000
+++ INSTALL
@@ -27,16 +27,16 @@ INSTALLING SBCL
   The following command installs SBCL and related documentation under
   the "/usr/local" directory (typically run as root):
 
-    # INSTALL_ROOT=/usr/local sh install.sh
+    # PREFIX=/usr/local sh install.sh
 
   You can also install SBCL as a user, under your home directory:
 
-    $ INSTALL_ROOT=/home/me sh install.sh
+    $ PREFIX=/home/me sh install.sh
 
   In other words, "install.sh" installs SBCL under the directory named
-  by the environment variable INSTALL_ROOT.
+  by the environment variable PREFIX.
 
-  If INSTALL_ROOT is not specified, SBCL is installed into location
+  If PREFIX is not specified, SBCL is installed into location
   configured at build-time: for official binary distributions under
   "/usr/local" directory.
 
@@ -59,7 +59,7 @@ INSTALLING SBCL
          $ export SBCL_HOME=/foo/bar/lib/sbcl
          $ sbcl
 
-       If your "INSTALL_ROOT" was FOO, then your "SBCL_HOME" is
+       If your "PREFIX" was FOO, then your "SBCL_HOME" is
        "FOO/lib/sbcl".
 
     3. By command line option:
$NetBSD$

--- install.sh.orig	2011-12-06 11:17:02.000000000 +0000
+++ install.sh
@@ -11,7 +11,8 @@ ensure_dirs ()
 }
 
 . output/prefix.def
-DEFAULT_INSTALL_ROOT=$SBCL_PREFIX
+
+PREFIX=${PREFIX-"${SBCL_PREFIX}"}
 
 if [ "$OSTYPE" = "cygwin" -o "$OSTYPE" = "msys" ] ; then
     RUNTIME=sbcl.exe
@@ -20,16 +21,15 @@ else
     RUNTIME=sbcl
     OLD_RUNTIME=sbcl.old
 fi
-INSTALL_ROOT=${INSTALL_ROOT-$DEFAULT_INSTALL_ROOT}
-MAN_DIR=${MAN_DIR-"$INSTALL_ROOT"/share/man}
-INFO_DIR=${INFO_DIR-"$INSTALL_ROOT"/share/info}
-DOC_DIR=${DOC_DIR-"$INSTALL_ROOT"/share/doc/sbcl}
+MAN_DIR=${MAN_DIR-"${PREFIX}"/share/man}
+INFO_DIR=${INFO_DIR-"${PREFIX}"/share/info}
+DOC_DIR=${DOC_DIR-"${PREFIX}"/share/doc/sbcl}
 
 # Does the environment look sane?
-if [ -n "$SBCL_HOME" -a "$INSTALL_ROOT/lib/sbcl" != "$SBCL_HOME" ];then
-   echo SBCL_HOME environment variable is set, and conflicts with INSTALL_ROOT.
+if [ -n "$SBCL_HOME" -a "${PREFIX}/lib/sbcl" != "$SBCL_HOME" ];then
+   echo SBCL_HOME environment variable is set, and conflicts with PREFIX.
    echo Aborting installation.  Unset one or reset the other, then try again
-   echo INSTALL_ROOT="$INSTALL_ROOT"
+   echo PREFIX="${PREFIX}"
    echo SBCL_HOME="$SBCL_HOME"
    exit 1
 fi
@@ -47,26 +47,26 @@ else
     exit 1
 fi
 
-SBCL_HOME="$INSTALL_ROOT"/lib/sbcl
-export SBCL_HOME INSTALL_ROOT
-ensure_dirs "$BUILD_ROOT$INSTALL_ROOT" "$BUILD_ROOT$INSTALL_ROOT"/bin \
-    "$BUILD_ROOT$INSTALL_ROOT"/lib  \
-    "$BUILD_ROOT$MAN_DIR" "$BUILD_ROOT$MAN_DIR"/man1 \
-    "$BUILD_ROOT$INFO_DIR" "$BUILD_ROOT$DOC_DIR" \
-    "$BUILD_ROOT$DOC_DIR"/html \
-    "$BUILD_ROOT$SBCL_HOME" \
-    "$BUILD_ROOT$SBCL_HOME"/site-systems
+SBCL_HOME="${PREFIX}"/lib/sbcl
+export SBCL_HOME PREFIX
+ensure_dirs "${DESTDIR}${PREFIX}" "${DESTDIR}${PREFIX}"/bin \
+    "${DESTDIR}${PREFIX}"/lib  \
+    "${DESTDIR}$MAN_DIR" "${DESTDIR}$MAN_DIR"/man1 \
+    "${DESTDIR}$INFO_DIR" "${DESTDIR}$DOC_DIR" \
+    "${DESTDIR}$DOC_DIR"/html \
+    "${DESTDIR}$SBCL_HOME" \
+    "${DESTDIR}$SBCL_HOME"/site-systems
 
 # move old versions out of the way.  Safer than copying: don't want to
 # break any running instances that have these files mapped
-test -f "$BUILD_ROOT$INSTALL_ROOT"/bin/$RUNTIME && \
- mv "$BUILD_ROOT$INSTALL_ROOT"/bin/$RUNTIME \
-    "$BUILD_ROOT$INSTALL_ROOT"/bin/$OLD_RUNTIME
-test -f "$BUILD_ROOT$SBCL_HOME"/sbcl.core && \
-    mv "$BUILD_ROOT$SBCL_HOME"/sbcl.core "$BUILD_ROOT$SBCL_HOME"/sbcl.core.old
+test -f "${DESTDIR}${PREFIX}"/bin/$RUNTIME && \
+ mv "${DESTDIR}${PREFIX}"/bin/$RUNTIME \
+    "${DESTDIR}${PREFIX}"/bin/$OLD_RUNTIME
+test -f "${DESTDIR}$SBCL_HOME"/sbcl.core && \
+    mv "${DESTDIR}$SBCL_HOME"/sbcl.core "${DESTDIR}$SBCL_HOME"/sbcl.core.old
 
-cp src/runtime/$RUNTIME "$BUILD_ROOT$INSTALL_ROOT"/bin/
-cp output/sbcl.core "$BUILD_ROOT$SBCL_HOME"/sbcl.core
+cp src/runtime/$RUNTIME "${DESTDIR}${PREFIX}"/bin/
+cp output/sbcl.core "${DESTDIR}$SBCL_HOME"/sbcl.core
 
 # installing contrib
 
@@ -84,13 +84,13 @@ for i in contrib/*; do
     test -d $i && test -f $i/test-passed || continue;
     INSTALL_DIR="$SBCL_HOME"/`basename $i `
     export INSTALL_DIR
-    ensure_dirs "$BUILD_ROOT$INSTALL_DIR" && $GNUMAKE -C $i install
+    ensure_dirs "${DESTDIR}$INSTALL_DIR" && $GNUMAKE -C $i install
 done
 
 echo
 echo "SBCL has been installed:"
-echo " binary $BUILD_ROOT$INSTALL_ROOT/bin/$RUNTIME"
-echo " core and contribs in $BUILD_ROOT$INSTALL_ROOT/lib/sbcl/"
+echo " binary ${DESTDIR}${PREFIX}/bin/$RUNTIME"
+echo " core and contribs in ${DESTDIR}${PREFIX}/lib/sbcl/"
 
 # Installing manual & misc bits of documentation
 #
@@ -106,46 +106,46 @@ echo
 echo "Documentation:"
 
 # man
-cp doc/sbcl.1 "$BUILD_ROOT$MAN_DIR"/man1/ && echo " man $BUILD_ROOT$MAN_DIR/man1/sbcl.1"
+cp doc/sbcl.1 "${DESTDIR}$MAN_DIR"/man1/ && echo " man ${DESTDIR}$MAN_DIR/man1/sbcl.1"
 
 # info
 for info in doc/manual/*.info
 do
-  cp $info "$BUILD_ROOT$INFO_DIR"/ \
+  cp $info "${DESTDIR}$INFO_DIR"/ \
       && BN=`basename $info` \
-      && DIRFAIL=`install-info --info-dir="$BUILD_ROOT$INFO_DIR" \
-        "$BUILD_ROOT$INFO_DIR"/$BN > /dev/null 2>&1 \
+      && DIRFAIL=`install-info --info-dir="${DESTDIR}$INFO_DIR" \
+        "${DESTDIR}$INFO_DIR"/$BN > /dev/null 2>&1 \
            || echo "(could not add to system catalog)"` \
-      && echo " info $BUILD_ROOT$INFO_DIR/`basename $info` [$BUILD_ROOT$INFO_DIR/dir] $DIRFAIL"
+      && echo " info ${DESTDIR}$INFO_DIR/`basename $info` [${DESTDIR}$INFO_DIR/dir] $DIRFAIL"
 done
 
 for info in doc/manual/*.info-*
 do
-  cp $info "$BUILD_ROOT$INFO_DIR"/ \
-      && echo " info $BUILD_ROOT$INFO_DIR/`basename $info`"
+  cp $info "${DESTDIR}$INFO_DIR"/ \
+      && echo " info ${DESTDIR}$INFO_DIR/`basename $info`"
 done
 
 # pdf
 for pdf in doc/manual/*.pdf
 do
-  cp $pdf "$BUILD_ROOT$DOC_DIR"/ \
-      && echo " pdf $BUILD_ROOT$DOC_DIR/`basename $pdf`"
+  cp $pdf "${DESTDIR}$DOC_DIR"/ \
+      && echo " pdf ${DESTDIR}$DOC_DIR/`basename $pdf`"
 done
 
 # html
 for html in doc/manual/sbcl doc/manual/asdf
 do
-  test -d $html && cp -R -L $html "$BUILD_ROOT$DOC_DIR"/html \
-      && echo " html $BUILD_ROOT$DOC_DIR/html/`basename $html`/index.html"
+  test -d $html && cp -R -L $html "${DESTDIR}$DOC_DIR"/html \
+      && echo " html ${DESTDIR}$DOC_DIR/html/`basename $html`/index.html"
 done
 
 for html in doc/manual/sbcl.html doc/manual/asdf.html
 do
-  cp $html "$BUILD_ROOT$DOC_DIR"/ \
-      && echo " html $BUILD_ROOT$DOC_DIR/`basename $html`"
+  cp $html "${DESTDIR}$DOC_DIR"/ \
+      && echo " html ${DESTDIR}$DOC_DIR/`basename $html`"
 done
 
 for f in BUGS CREDITS COPYING NEWS
 do
-  cp $f "$BUILD_ROOT$DOC_DIR"/
+  cp $f "${DESTDIR}$DOC_DIR"/
 done
$NetBSD$

--- contrib/asdf-module.mk.orig	2011-12-06 13:56:29.000000000 +0000
+++ contrib/asdf-module.mk
@@ -37,5 +37,5 @@ test: all
 # KLUDGE: There seems to be no portable way to tell tar to not to
 # preserve owner, so chown after installing for the current user.
 install: $(EXTRA_INSTALL_TARGETS)
-	tar cf - . | ( cd "$(BUILD_ROOT)$(INSTALL_DIR)" && tar xpvf - )
-	find "$(BUILD_ROOT)$(INSTALL_DIR)" -exec chown `id -u`:`id -g` {} \;
+	tar cf - . | ( cd "$(DESTDIR)$(INSTALL_DIR)" && tar xpvf - )
+	find "$(DESTDIR)$(INSTALL_DIR)" -exec chown `id -u`:`id -g` {} \;
$NetBSD$

--- contrib/vanilla-module.mk.orig	2011-12-06 11:17:02.000000000 +0000
+++ contrib/vanilla-module.mk
@@ -5,4 +5,4 @@ $(MODULE).fasl: $(MODULE).lisp ../../out
 test:: $(MODULE).fasl
 
 install:
-	cp $(MODULE).fasl "$(BUILD_ROOT)$(INSTALL_DIR)"
+	cp $(MODULE).fasl "$(DESTDIR)$(INSTALL_DIR)"
$NetBSD$

--- contrib/STANDARDS.orig	2011-12-06 11:17:02.000000000 +0000
+++ contrib/STANDARDS
@@ -49,7 +49,7 @@ A contrib package must contain a Makefil
 
 all:     # do whatever compilation is necessary
 test:    # run the package tests
-install: # copy all necessary files into $(BUILD_ROOT)$(INSTALL_DIR)
+install: # copy all necessary files into $(DESTDIR)$(INSTALL_DIR)
 
 If the contrib package involves more than one file, you are encouraged
 to use ASDF to build it and load it.  A version of asdf is bundled as
@@ -58,7 +58,7 @@ files - your install target should creat
 to the installed location of the system file.  Look in
 sb-bsd-sockets/Makefile for an example of an asdf-using contrib.
 
-$(BUILD_ROOT)$(INSTALL_DIR) will have been created by the system
+$(DESTDIR)$(INSTALL_DIR) will have been created by the system
 before your install target is called.  You do not need to make it
 yourself.