diff -urpN leveldb-1.15.0.orig/build_detect_platform leveldb-1.15.0/build_detect_platform
--- leveldb-1.15.0.orig/build_detect_platform	2014-03-24 19:08:03.861562520 -0700
+++ leveldb-1.15.0/build_detect_platform	2014-03-24 19:09:21.064911973 -0700
@@ -170,13 +170,18 @@ if [ "$CROSS_COMPILE" = "true" ]; then
     true
 else
     CXXOUTPUT="${TMPDIR}/leveldb_build_detect_platform-cxx.$$"
-
+  if [ "${USE_CXX0X:-auto}" = "auto" ]; then
     # If -std=c++0x works, use <cstdatomic>.  Otherwise use port_posix.h.
     $CXX $CXXFLAGS -std=c++0x -x c++ - -o $CXXOUTPUT 2>/dev/null  <<EOF
       #include <cstdatomic>
       int main() {}
 EOF
     if [ "$?" = 0 ]; then
+	USE_CXX0X="yes"
+    fi
+  fi
+
+    if [ "$USE_CXX0X" = "yes" ]; then
         COMMON_FLAGS="$COMMON_FLAGS -DLEVELDB_PLATFORM_POSIX -DLEVELDB_CSTDATOMIC_PRESENT"
         PLATFORM_CXXFLAGS="-std=c++0x"
     else
@@ -185,20 +190,32 @@ EOF
 
     # Test whether Snappy library is installed
     # http://code.google.com/p/snappy/
+  if [ "${USE_SNAPPY:-auto}" = "auto" ]; then
     $CXX $CXXFLAGS -x c++ - -o $CXXOUTPUT 2>/dev/null  <<EOF
       #include <snappy.h>
       int main() {}
 EOF
     if [ "$?" = 0 ]; then
+	USE_SNAPPY="yes"
+    fi
+  fi
+
+    if [ "$USE_SNAPPY" = "yes" ]; then
         COMMON_FLAGS="$COMMON_FLAGS -DSNAPPY"
         PLATFORM_LIBS="$PLATFORM_LIBS -lsnappy"
     fi
 
     # Test whether tcmalloc is available
+  if [ "${USE_TCMALLOC:-auto}" = "auto" ]; then
     $CXX $CXXFLAGS -x c++ - -o $CXXOUTPUT -ltcmalloc 2>/dev/null  <<EOF
       int main() {}
 EOF
     if [ "$?" = 0 ]; then
+	USE_TCMALLOC="yes"
+    fi
+  fi
+
+    if [ "$USE_TCMALLOC" = "yes" ]; then
         PLATFORM_LIBS="$PLATFORM_LIBS -ltcmalloc"
     fi