diff --git a/corepkgs/nar/nar.sh b/corepkgs/nar/nar.sh
index 059bca8ba..a7b6be8aa 100644
--- a/corepkgs/nar/nar.sh
+++ b/corepkgs/nar/nar.sh
@@ -1,3 +1,5 @@
 #! /bin/sh
 
+echo "packing $path into $out..."
 /nix/bin/nix --dump --file "$path" | bzip2 > $out || exit 1
+
diff --git a/scripts/nix-push.in b/scripts/nix-push.in
index fdb432303..bb25019e8 100644
--- a/scripts/nix-push.in
+++ b/scripts/nix-push.in
@@ -8,6 +8,8 @@ foreach my $id (@ARGV) {
 
     # Get all paths referenced by the normalisation of the given 
     # fstate expression.
+    system "nix -ih $id";
+    if ($?) { die "`nix -ih' failed"; }
     my @paths;
     open PATHS, "nix -qrh $id 2> /dev/null |" or die "nix -qrh";
     while (<PATHS>) {
@@ -51,6 +53,8 @@ foreach my $id (@ARGV) {
         die unless $nid =~ /^([0-9a-z]{32})$/;
 
         # Realise the Nix expression.
+	system "nix -ih $nid";
+	if ($?) { die "`nix -ih' failed"; }
         my $npath = `nix -qph $nid 2> /dev/null`;
         $? and die "creating Nix archive";
         chomp $npath;
diff --git a/src/nix.cc b/src/nix.cc
index ae016824d..fe762798e 100644
--- a/src/nix.cc
+++ b/src/nix.cc
@@ -216,8 +216,12 @@ struct StdoutSink : DumpSink
     virtual void operator ()
         (const unsigned char * data, unsigned int len)
     {
-        if (write(STDOUT_FILENO, (char *) data, len) != (ssize_t) len)
-            throw SysError("writing to stdout");
+        while (len) {
+            ssize_t res = write(STDOUT_FILENO, (char *) data, len);
+            if (res == -1) throw SysError("writing to stdout");
+            len -= res;
+            data += res;
+        }
     }
 };
 
@@ -249,7 +253,7 @@ struct StdinSource : RestoreSource
         while (len) {
             ssize_t res = read(STDIN_FILENO, (char *) data, len);
             if (res == -1) throw SysError("reading from stdin");
-            if (res == 0) throw SysError("unexpected end-of-file on stdin");
+            if (res == 0) throw Error("unexpected end-of-file on stdin");
             len -= res;
             data += res;
         }