diff --git a/README.md b/README.md
index 0d35507..746da20 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ Basically everything you can build on OS X with clang/gcc should build with this
 ### PACKET MANAGERS ###
 
 OSXCross comes with a minimalistic MacPorts Packet Manager.  
-Please see [README.MACPORTS](https://github.com/tpoechtrager/osxcross/blob/master/README.MACPORTS.md) for more.
+Please see [README.MACPORTS](README.MACPORTS.md) for more.
 
 ### INSTALLATION: ###
 
diff --git a/build.sh b/build.sh
index 370558d..9c6c93b 100755
--- a/build.sh
+++ b/build.sh
@@ -26,8 +26,8 @@ function guess_sdk_version()
     exit 1
   else
     sdk=$(find -L tarballs/ -type f | grep MacOSX)
-    tmp2=$(echo ${sdk/bz2/} | sed s/[^0-9.]//g)
-    tmp3=$(echo $tmp2 | sed s/\\\.*$//g)
+    tmp2=$(echo ${sdk/bz2/} | $SED s/[^0-9.]//g)
+    tmp3=$(echo $tmp2 | $SED s/\\\.*$//g)
     guess_sdk_version_result=$tmp3
     echo 'found SDK version' $guess_sdk_version_result 'at tarballs/'$(basename $sdk)
   fi
@@ -117,7 +117,6 @@ require $CXX
 
 require clang
 require patch
-require sed
 require gunzip
 
 pushd $BUILD_DIR &>/dev/null
@@ -188,12 +187,12 @@ CCTOOLS=$(find . -name "x86_64-apple-darwin*")
 CCTOOLS=($CCTOOLS)
 if [ $X86_64H_SUPPORTED -eq 1 ]; then
   for CCTOOL in ${CCTOOLS[@]}; do
-    CCTOOL_X86_64H=$(echo "$CCTOOL" | sed 's/x86_64/x86_64h/g')
+    CCTOOL_X86_64H=$(echo "$CCTOOL" | $SED 's/x86_64/x86_64h/g')
     ln -sf $CCTOOL $CCTOOL_X86_64H
   done
 fi
 for CCTOOL in ${CCTOOLS[@]}; do
-  CCTOOL_I386=$(echo "$CCTOOL" | sed 's/x86_64/i386/g')
+  CCTOOL_I386=$(echo "$CCTOOL" | $SED 's/x86_64/i386/g')
   ln -sf $CCTOOL $CCTOOL_I386
 done
 popd &>/dev/null
diff --git a/build_binutils.sh b/build_binutils.sh
index 5232172..ee7a7d1 100755
--- a/build_binutils.sh
+++ b/build_binutils.sh
@@ -6,7 +6,7 @@ DESC=binutils
 USESYSTEMCOMPILER=1
 source tools/tools.sh
 
-`tools/osxcross_conf.sh`
+eval $(tools/osxcross_conf.sh)
 
 # binutils version to build
 BINUTILS_VERSION=2.25
diff --git a/build_compiler_rt.sh b/build_compiler_rt.sh
index f380ccc..65267ee 100755
--- a/build_compiler_rt.sh
+++ b/build_compiler_rt.sh
@@ -10,7 +10,6 @@ if [ $PLATFORM == "Darwin" ]; then
 fi
 
 require git
-require $MAKE
 
 set +e
 
@@ -31,35 +30,24 @@ set -e
 CLANG_VERSION=$(echo "__clang_major__ __clang_minor__ __clang_patchlevel__" | \
  clang -xc -E - | tail -n1 | tr ' ' '.')
 
-if [[ $PLATFORM == CYGWIN* ]] && [[ $(which clang) == "/usr/bin/clang" ]]; then
-  CLANG_LIB_DIR="/usr/lib/clang/$(uname -m)-pc-cygwin"
-else
-  set +e
-  which llvm-config &>/dev/null && { CLANG_LIB_DIR=$(llvm-config --libdir); }
-  set -e
-
-  if [ -z "$CLANG_LIB_DIR" ]; then
-    require $READLINK
-    CLANG_LIB_DIR="$(dirname $($READLINK -f $(which clang)))/../lib"
-  fi
-
-  CLANG_LIB_DIR+="/clang"
-fi
-
-if [ ! -d "$CLANG_LIB_DIR" ]; then
-  echo "$CLANG_LIB_DIR does not exist!" 1>&2
-  echo "Installing llvm-dev may help" 1>&2
-  exit 1
-fi
-
 # Drop patch level for <= 3.3.
 if [ $(osxcross-cmp $CLANG_VERSION "<=" 3.3) -eq 1 ]; then
   CLANG_VERSION=$(echo $CLANG_VERSION | tr '.' ' ' |
                   awk '{print $1, $2}' | tr ' ' '.')
 fi
 
-CLANG_INCLUDE_DIR="${CLANG_LIB_DIR}/${CLANG_VERSION}/include"
-CLANG_DARWIN_LIB_DIR="${CLANG_LIB_DIR}/${CLANG_VERSION}/lib/darwin"
+CLANG_LIB_DIR=$(clang -print-search-dirs | grep "libraries: =" | \
+                tr '=' ' ' | tr ':' ' ' | awk '{print $2}')
+
+VERSION=$(echo "${CLANG_LIB_DIR}" | tr '/' '\n' | tail -n1)
+
+if [ $VERSION != $CLANG_VERSION ]; then
+  echo "sanity check failed: $VERSION != ${CLANG_VERSION}" 1>&2
+  exit 1
+fi
+
+CLANG_INCLUDE_DIR="${CLANG_LIB_DIR}/include"
+CLANG_DARWIN_LIB_DIR="${CLANG_LIB_DIR}/lib/darwin"
 
 case $CLANG_VERSION in
   3.2*) BRANCH=release_32 ;;
@@ -95,7 +83,7 @@ $SED -i "s/Configs += asan_iossim_dynamic//g" make/platform/clang_darwin.mk
 
 # Unbreak the -Werror build.
 if [ -f lib/asan/asan_mac.h ]; then
-  sed -i "s/ASAN__MAC_H/ASAN_MAC_H/g" lib/asan/asan_mac.h
+  $SED -i "s/ASAN__MAC_H/ASAN_MAC_H/g" lib/asan/asan_mac.h
 fi
 
 if [ $(osxcross-cmp $CLANG_VERSION ">=" 3.5) -eq 1 ]; then
@@ -111,12 +99,12 @@ then
   exit 1
 fi
 
-EXTRA_MAKE_FLAGS="LIPO=\"xcrun lipo\""
+EXTRA_MAKE_FLAGS="LIPO=\"$(xcrun -f lipo)\""
 
 if [ $(osxcross-cmp $CLANG_VERSION "<=" 3.3) -eq 1 ]; then
-  EXTRA_MAKE_FLAGS+=" AR=\"xcrun ar\""
-  EXTRA_MAKE_FLAGS+=" RANLIB=\"xcrun ranlib\""
-  EXTRA_MAKE_FLAGS+=" CC=\"xcrun clang\""
+  EXTRA_MAKE_FLAGS+=" AR=\"$(xcrun -f ar)\""
+  EXTRA_MAKE_FLAGS+=" RANLIB=\"$(xcrun -f ranlib)\""
+  EXTRA_MAKE_FLAGS+=" CC=\"$(xcrun -f clang)\""
 fi
 
 if [ -n "$OCDEBUG" ]; then
@@ -135,8 +123,8 @@ echo ""
 echo "Please run the following commands by hand to install compiler-rt:"
 echo ""
 
-echo "mkdir -p ${CLANG_LIB_DIR}/${CLANG_VERSION}/include"
-echo "mkdir -p ${CLANG_LIB_DIR}/${CLANG_VERSION}/lib/darwin"
+echo "mkdir -p ${CLANG_INCLUDE_DIR}"
+echo "mkdir -p ${CLANG_DARWIN_LIB_DIR}"
 echo "cp -r $PWD/include/sanitizer ${CLANG_INCLUDE_DIR}"
 
 pushd "clang_darwin" &>/dev/null
diff --git a/build_gcc.sh b/build_gcc.sh
index 73bcbfb..053143c 100755
--- a/build_gcc.sh
+++ b/build_gcc.sh
@@ -8,7 +8,7 @@ DESC=gcc
 USESYSTEMCOMPILER=1
 source tools/tools.sh
 
-`tools/osxcross_conf.sh`
+eval $(tools/osxcross_conf.sh)
 
 # GCC version to build
 # (<4.7 will not work properly with libc++)
diff --git a/tools/get_cpu_count.sh b/tools/get_cpu_count.sh
index e406d78..adb579a 100755
--- a/tools/get_cpu_count.sh
+++ b/tools/get_cpu_count.sh
@@ -15,4 +15,4 @@ esac
 
 [ ! -f $prog ] && cc cpucount.c -o cpucount &>/dev/null
 
-eval "./${prog}"
+./$prog
diff --git a/tools/tools.sh b/tools/tools.sh
index a506e72..b0c85c1 100755
--- a/tools/tools.sh
+++ b/tools/tools.sh
@@ -59,7 +59,9 @@ test -n "$OCDEBUG" && set -x
 
 if [[ $SCRIPT != *wrapper/build.sh ]]; then
   # how many concurrent jobs should be used for compiling?
-  JOBS=${JOBS:=$(tools/get_cpu_count.sh)}
+  if [ -z "$JOBS" ]; then
+    JOBS=$(tools/get_cpu_count.sh || echo 1)
+  fi
 
   if [ $SCRIPT != "build.sh" -a $SCRIPT != "build_clang.sh" -a \
        $SCRIPT != "mount_xcode_image.sh" -a \
@@ -95,22 +97,12 @@ function require()
 
 if [[ $PLATFORM == *BSD ]] || [ $PLATFORM == "DragonFly" ]; then
   MAKE=gmake
-else
-  MAKE=make
-fi
-
-if [[ $PLATFORM == OpenBSD ]]; then
   SED=gsed
 else
+  MAKE=make
   SED=sed
 fi
 
-if [[ $PLATFORM == *BSD ]] || [ $PLATFORM == "Darwin" ]; then
-  READLINK=greadlink
-else
-  READLINK=readlink
-fi
-
 require $SED
 require $MAKE