* Improved Nix. Resources (package descriptors and other source

files) are now referenced using their cryptographic hashes.  

  This ensures that if two package descriptors have the same contents,
  then they describe the same package.  This property is not as
  trivial as it sounds: generally import relations cause this property
  not to hold w.r.t. temporality.  But since imports also use hashes
  to reference other packages, equality follows by induction.

sys/start

@@ -4,7 +4,7 @@
 export PATH=/pkg/sys/bin
 
 # Add in the utilities needed for booting.
-export PATH=$PATH:`nix get-pkg prog-bootstrap`/bin
+export PATH=$PATH:`nix getpkg 5703121fe19cbeeaee7edd659cf4a25b`/bin
 
 echo
 echo Starting up...
@@ -14,17 +14,15 @@ mount -n -o remount,rw /dev/root /
 mount -n -t proc none /proc
 mount -n -t hostfs none /mnt/host 
 
-echo Registering available src packages...
-( cd /src
-  for i in *; do
-    if test -d $i; then
-      echo "  $i"
-      nix register-pkg $i /src/$i
-    fi
-  done
+echo Registering available sources...
+( if cd /src; then
+    for i in *; do
+      nix reg $i
+    done
+  fi
 )
 
-export PATH=`nix get-pkg coreutils-4.5.7`/bin:$PATH
+export PATH=`nix getpkg coreutils-4.5.7`/bin:$PATH
 
 echo
 echo "=== starting interactive shell ==="