diff --git a/pkgs/build-support/gcc-wrapper/builder.sh b/pkgs/build-support/gcc-wrapper/builder.sh
index 352a5895135f..5da6af4bdb60 100755
--- a/pkgs/build-support/gcc-wrapper/builder.sh
+++ b/pkgs/build-support/gcc-wrapper/builder.sh
@@ -56,6 +56,7 @@ ln -s g77 $out/bin/f77
 
 
 sed \
+    -e "s^@out@^$out^g" \
     -e "s^@ldflags@^$ldflags^g" \
     -e "s^@ld@^$ldPath/ld^g" \
     < $ldWrapper > $out/bin/ld
@@ -63,7 +64,7 @@ chmod +x $out/bin/ld
 
 
 mkdir $out/nix-support
-test -z "$gcc" && echo $gcc > $out/nix-support/orig-gcc
+test -n "$gcc" && echo $gcc > $out/nix-support/orig-gcc
 test -n "$glibc" && echo $glibc > $out/nix-support/orig-glibc
 
 cat > $out/nix-support/add-flags <<EOF
@@ -77,3 +78,5 @@ sed \
     -e "s^@binutils@^$binutils^g" \
     -e "s^@glibc@^$glibc^g" \
     < $setupHook > $out/nix-support/setup-hook
+
+cp -p $utils $out/nix-support/utils
\ No newline at end of file
diff --git a/pkgs/build-support/gcc-wrapper/default.nix b/pkgs/build-support/gcc-wrapper/default.nix
index a9c3f3382b85..304f919138f3 100644
--- a/pkgs/build-support/gcc-wrapper/default.nix
+++ b/pkgs/build-support/gcc-wrapper/default.nix
@@ -19,6 +19,7 @@ derivation {
   setupHook = ./setup-hook.sh;
   gccWrapper = ./gcc-wrapper.sh;
   ldWrapper = ./ld-wrapper.sh;
+  utils = ./utils.sh;
   inherit name stdenv nativeTools nativeGlibc nativePrefix gcc glibc binutils;
   langC = if nativeTools then true else gcc.langC;
   langCC = if nativeTools then true else gcc.langCC;
diff --git a/pkgs/build-support/gcc-wrapper/gcc-wrapper.sh b/pkgs/build-support/gcc-wrapper/gcc-wrapper.sh
index 29d3ffb8e492..d144e142d214 100644
--- a/pkgs/build-support/gcc-wrapper/gcc-wrapper.sh
+++ b/pkgs/build-support/gcc-wrapper/gcc-wrapper.sh
@@ -8,13 +8,15 @@ if test -z "$NIX_GLIBC_FLAGS_SET"; then
     . @out@/nix-support/add-flags
 fi
 
+. @out@/nix-support/utils
+
 
 # Figure out if linker flags should be passed.  GCC prints annoying
 # warnings when they are not needed.
 dontLink=0
 if test "$*" = "-v" -o -z "$*"; then
     dontLink=1
-else    
+else
     for i in "$@"; do
         if test "$i" = "-c"; then
             dontLink=1
@@ -34,19 +36,8 @@ fi
 
 
 # Optionally filter out paths not refering to the store.
-skip () {
-    if test "$NIX_DEBUG" = "1"; then
-        echo "skipping impure path $1" >&2
-    fi
-}
-
-badPath() {
-    p=$1
-    test "${p:0:${#NIX_STORE}}" = "$NIX_STORE" -o "${p:0:4}" = "/tmp"
-}
-
 params=("$@")
-if test "$NIX_ENFORCE_PURITY" = "1x" -a -n "$NIX_STORE"; then
+if test "$NIX_ENFORCE_PURITY" = "1" -a -n "$NIX_STORE"; then
     rest=()
     n=0
     while test $n -lt ${#params[*]}; do
diff --git a/pkgs/build-support/gcc-wrapper/ld-wrapper.sh b/pkgs/build-support/gcc-wrapper/ld-wrapper.sh
index bf59b2a8afbb..45bb210aa6d9 100644
--- a/pkgs/build-support/gcc-wrapper/ld-wrapper.sh
+++ b/pkgs/build-support/gcc-wrapper/ld-wrapper.sh
@@ -4,30 +4,29 @@ if test -n "$NIX_LD_WRAPPER_START_HOOK"; then
     . "$NIX_LD_WRAPPER_START_HOOK"
 fi
 
-# Optionally filter out paths not refering to the store.
-skip () {
-    if test "$NIX_DEBUG" = "1"; then
-        echo "skipping impure path $1" >&2
-    fi
-}
+. @out@/nix-support/utils
 
+
+# Optionally filter out paths not refering to the store.
 params=("$@")
-if test "$NIX_ENFORCE_PURITY" = "1x" -a -n "$NIX_STORE"; then
+if test "$NIX_ENFORCE_PURITY" = "1" -a -n "$NIX_STORE"; then
     rest=()
     n=0
     while test $n -lt ${#params[*]}; do
         p=${params[n]}
         p2=${params[$((n+1))]}
-        if test "${p:0:3}" = "-L/" -a "${p:2:${#NIX_STORE}}" != "$NIX_STORE"; then
+        if test "${p:0:3}" = "-L/" && badPath "${p:2}"; then
             skip $p
-        elif test "$p" = "-L" -a "${p2:0:${#NIX_STORE}}" != "$NIX_STORE"; then
+        elif test "$p" = "-L" && badPath "$p2"; then
             n=$((n + 1)); skip $p2
-        elif test "$p" = "-dynamic-linker" -a "${p2:0:${#NIX_STORE}}" != "$NIX_STORE"; then
+        elif test "$p" = "-rpath" && badPath "$p2"; then
             n=$((n + 1)); skip $p2
-#        elif test "${p:0:1}" = "/" -a "${p:0:${#NIX_STORE}}" != "$NIX_STORE"; then
-#            # We cannot skip this; barf.
-#            echo "impure path \`$p' used in link"
-#            exit 1
+        elif test "$p" = "-dynamic-linker" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        elif test "${p:0:1}" = "/" && badPath "$p"; then
+            # We cannot skip this; barf.
+            echo "impure path \`$p' used in link" >&2
+            exit 1
         else
             rest=("${rest[@]}" "$p")
         fi
@@ -43,6 +42,7 @@ if test -z "$NIX_LDFLAGS_SET"; then
     extra=(${extra[@]} $NIX_LDFLAGS)
 fi
 
+# Optionally print debug info.
 if test "$NIX_DEBUG" = "1"; then
   echo "original flags to @ld@:" >&2
   for i in "${params[@]}"; do
diff --git a/pkgs/build-support/gcc-wrapper/utils.sh b/pkgs/build-support/gcc-wrapper/utils.sh
new file mode 100644
index 000000000000..5163c239527c
--- /dev/null
+++ b/pkgs/build-support/gcc-wrapper/utils.sh
@@ -0,0 +1,13 @@
+skip () {
+    if test "$NIX_DEBUG" = "1"; then
+        echo "skipping impure path $1" >&2
+    fi
+}
+
+badPath() {
+    local p=$1
+    test \
+        "${p:0:${#NIX_STORE}}" != "$NIX_STORE" -a \
+        "${p:0:4}" != "/tmp" -a \
+        "${p:0:${#NIX_BUILD_TOP}}" != "$NIX_BUILD_TOP"
+}
diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index 21611278c21b..2dedf46ac2b3 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -69,8 +69,6 @@ addToEnv()
         export _PATH=$_PATH:$1/bin
     fi
 
-    echo "${envHooks[@]}"
-
     for i in "${envHooks[@]}"; do
         $i $pkg
     done
@@ -92,8 +90,20 @@ export NIX_STRIP_DEBUG=1
 export NIX_CFLAGS_STRIP="-g0 -Wl,-s"
 
 
-# Where is the store?  This is required for purity checking.
-export NIX_STORE=$(dirname $out)/ # !!! hack
+# Do we know where the store is?  This is required for purity checking.
+if test -z "$NIX_STORE"; then
+    echo "Error: you have an old version of Nix that does not set the" \
+        "NIX_STORE variable.  Please upgrade." >&2
+    exit 1
+fi
+
+
+# We also need to know the root of the build directory for purity checking.
+if test -z "$NIX_BUILD_TOP"; then
+    echo "Error: you have an old version of Nix that does not set the" \
+        "NIX_BUILD_TOP variable.  Please upgrade." >&2
+    exit 1
+fi
 
 
 # Set the TZ (timezone) environment variable, otherwise commands like
diff --git a/pkgs/stdenv/nix-linux/boot.nix b/pkgs/stdenv/nix-linux/boot.nix
index b104add43184..2e1f272fc603 100644
--- a/pkgs/stdenv/nix-linux/boot.nix
+++ b/pkgs/stdenv/nix-linux/boot.nix
@@ -1,19 +1,17 @@
-{stdenv, pkgs, glibc}:
+{stdenv, glibc}:
 
 (import ../generic) {
   name = "stdenv-nix-linux-boot";
   preHook = ./prehook-boot.sh;
-  initialPath = (import ../nix/path.nix) {pkgs = pkgs;};
+  initialPath = "/usr/local /usr /";
 
   inherit stdenv;
 
   gcc = (import ../../build-support/gcc-wrapper) {
-    name = pkgs.gcc.name;
-    nativeTools = false;
+    name = "gcc-native";
+    nativeTools = true;
     nativeGlibc = false;
-    inherit (pkgs) gcc binutils;
+    nativePrefix = "/usr";
     inherit stdenv glibc;
   };
-
-  param1 = pkgs.bash;
 }
diff --git a/pkgs/stdenv/nix-linux/default.nix b/pkgs/stdenv/nix-linux/default.nix
index ecbbc488cb4d..7219ae05726b 100644
--- a/pkgs/stdenv/nix-linux/default.nix
+++ b/pkgs/stdenv/nix-linux/default.nix
@@ -1,13 +1,13 @@
-{stdenv, glibc, pkgs}:
+{stdenv, glibc, pkgs, genericStdenv, gccWrapper}:
 
-(import ../generic) {
+genericStdenv {
   name = "stdenv-nix-linux";
   preHook = ./prehook.sh;
   initialPath = (import ../nix/path.nix) {pkgs = pkgs;};
 
   inherit stdenv;
 
-  gcc = (import ../../build-support/gcc-wrapper) {
+  gcc = gccWrapper {
     name = pkgs.gcc.name;
     nativeTools = false;
     nativeGlibc = false;
diff --git a/pkgs/stdenv/nix-linux/prehook-boot.sh b/pkgs/stdenv/nix-linux/prehook-boot.sh
index 33f8bc0bb6e3..21248e16cdb2 100644
--- a/pkgs/stdenv/nix-linux/prehook-boot.sh
+++ b/pkgs/stdenv/nix-linux/prehook-boot.sh
@@ -1,3 +1,3 @@
-export SHELL=$param1
+export SHELL=/bin/sh
 
 export NIX_ENFORCE_PURITY=
diff --git a/pkgs/system/stdenvs.nix b/pkgs/system/stdenvs.nix
index e3381090f037..ecf8fa0f5280 100644
--- a/pkgs/system/stdenvs.nix
+++ b/pkgs/system/stdenvs.nix
@@ -7,6 +7,9 @@
 
 {system, allPackages}: rec {
 
+  gccWrapper = import ../build-support/gcc-wrapper;
+  genericStdenv = import ../stdenv/generic;
+
 
   # Trivial environment used for building other environments.
   stdenvInitial = (import ../stdenv/initial) {
@@ -45,7 +48,6 @@
   #    plus the pure glibc.
   stdenvLinuxBoot1 = (import ../stdenv/nix-linux/boot.nix) {
     stdenv = stdenvNative;
-    pkgs = allPackages {stdenv = stdenvNative; noSysDirs = false;};
     glibc = stdenvLinuxGlibc;
   };
 
@@ -60,6 +62,7 @@
     stdenv = stdenvLinuxBoot1;
     pkgs = stdenvLinuxBoot1Pkgs;
     glibc = stdenvLinuxGlibc;
+    inherit genericStdenv gccWrapper;
   };
 
   # 5) These packages should be pure.
@@ -70,6 +73,7 @@
     stdenv = stdenvLinuxBoot2;
     pkgs = stdenvLinuxBoot2Pkgs;
     glibc = stdenvLinuxGlibc;
+    inherit genericStdenv gccWrapper;
   };
 
   # 7) And we can build all packages against that, but we don't
diff --git a/pkgs/test/simple/builder.sh b/pkgs/test/simple/builder.sh
index cfc895ac1392..f97356a55630 100755
--- a/pkgs/test/simple/builder.sh
+++ b/pkgs/test/simple/builder.sh
@@ -6,10 +6,7 @@ export NIX_DEBUG=1
 
 . $stdenv/setup
 
-#echo starting shell
-#/bin/sh < /dev/tty > /dev/tty 2>&1 
-
-#exit 1
+export NIX_ENFORCE_PURITY=1
 
 mkdir $out
 mkdir $out/bin
@@ -25,7 +22,7 @@ int main(int argc, char * * argv)
 EOF
 
 #gcc -I/nix/store/foo -I /nix/store/foo -I/usr/lib -I /usr/lib hello.c -o $out/bin/hello
-gcc -L /nix/store/abcd/lib -isystem /usr/lib hello.c -o $out/bin/hello
+gcc -I`pwd` -L /nix/store/abcd/lib -isystem /usr/lib hello.c -o $out/bin/hello
 
 $out/bin/hello
 
diff --git a/pkgs/test/simple/default.nix b/pkgs/test/simple/default.nix
index 39b0416fc9a1..0201097dc7d3 100644
--- a/pkgs/test/simple/default.nix
+++ b/pkgs/test/simple/default.nix
@@ -6,7 +6,7 @@ let {
     allPackages = import ../../system/all-packages-generic.nix;
   };
 
-  stdenv = stdenvs.stdenvLinuxBoot2;
+  stdenv = stdenvs.stdenvLinux;
 
   test = derivation {
     name = "simple-test";