diff --git a/lib/test-driver/Machine.pm b/lib/test-driver/Machine.pm
index 28596a5d634..b9dae819b49 100644
--- a/lib/test-driver/Machine.pm
+++ b/lib/test-driver/Machine.pm
@@ -251,7 +251,8 @@ sub execute {
     my $out = "";
 
     while (1) {
-        my $line = readline($self->{socket}) or die "connection to VM lost unexpectedly";
+        my $line = readline($self->{socket});
+        die "connection to VM lost unexpectedly" unless defined $line;
         #$self->log("got line: $line");
         if ($line =~ /^(.*)\|\!\=EOF\s+(\d+)$/) {
             $out .= $1;
@@ -270,7 +271,7 @@ sub succeed {
         my ($status, $out) = $self->execute($command);
         if ($status != 0) {
             $self->log("output: $out");
-            die "command `$command' did not succeed (exit code $status)";
+            die "command `$command' did not succeed (exit code $status)\n";
         }
         $res .= $out;
     }
@@ -407,7 +408,8 @@ sub unblock {
 # Take a screenshot of the X server on :0.0.
 sub screenshot {
     my ($self, $filename) = @_;
-    $filename = "$ENV{'out'}/${filename}.png" if $filename =~ /^\w+$/;
+    my $dir = $ENV{'out'} || Cwd::abs_path(".");
+    $filename = "$dir/${filename}.png" if $filename =~ /^\w+$/;
     my $tmp = "${filename}.ppm";
     $self->sendMonitorCommand("screendump $tmp");
     system("convert $tmp ${filename}") == 0
diff --git a/lib/test-driver/test-driver.pl b/lib/test-driver/test-driver.pl
index ad1af5a6fbf..6735b52dd69 100644
--- a/lib/test-driver/test-driver.pl
+++ b/lib/test-driver/test-driver.pl
@@ -1,8 +1,13 @@
+#! @perl@ -w -I@libDir@ -I@readline@
+
 use strict;
 use Machine;
+use Term::ReadLine;
 
 $SIG{PIPE} = 'IGNORE'; # because Unix domain sockets may die unexpectedly
 
+$ENV{PATH} = "@extraPath@:$ENV{PATH}";
+
 STDERR->autoflush(1);
 
 my %vms;
@@ -26,10 +31,13 @@ sub runTests {
         eval "$context $ENV{tests}";
         die $@ if $@;
     } else {
-        while (<STDIN>) {
+        my $term = Term::ReadLine->new('nixos-vm-test');
+        $term->ReadHistory;
+        while (defined ($_ = $term->readline("> "))) {
             eval "$context $_\n";
             warn $@ if $@;
         }
+        $term->WriteHistory;
     }
 
     # Copy the kernel coverage data for each machine, if the kernel
diff --git a/lib/testing.nix b/lib/testing.nix
index 02c011c5bc8..f7c25d938a8 100644
--- a/lib/testing.nix
+++ b/lib/testing.nix
@@ -8,6 +8,27 @@ rec {
   inherit pkgs;
 
 
+  testDriver = stdenv.mkDerivation {
+    name = "nixos-test-driver";
+    buildCommand =
+      ''
+        mkdir -p $out/bin
+        cp ${./test-driver/test-driver.pl} $out/bin/nixos-test-driver
+        chmod u+x $out/bin/nixos-test-driver
+        
+        libDir=$out/lib/perl5/site_perl
+        mkdir -p $libDir
+        cp ${./test-driver/Machine.pm} $libDir/Machine.pm
+
+        substituteInPlace $out/bin/nixos-test-driver \
+          --subst-var-by perl "${perl}/bin/perl" \
+          --subst-var-by readline "${perlPackages.TermReadLineGnu}/lib/perl5/site_perl" \
+          --subst-var-by extraPath "${imagemagick}/bin" \
+          --subst-var libDir
+      '';
+  };
+
+
   # Run an automated test suite in the given virtual network.
   # `network' must be the result of a call to the
   # `buildVirtualNetwork' function.  `tests' is a Perl fragment
@@ -20,15 +41,13 @@ rec {
       
       inherit tests;
       
-      buildInputs = [ pkgs.qemu_kvm pkgs.imagemagick ];
+      buildInputs = [ pkgs.qemu_kvm ];
 
       buildCommand =
         ''
-          mkdir $out
-          cp ${./test-driver/Machine.pm} Machine.pm
           ensureDir $out/nix-support
-          
-          ${perl}/bin/perl ${./test-driver/test-driver.pl} ${network}/vms/*/bin/run-*-vm
+
+          ${testDriver}/bin/nixos-test-driver ${network}/vms/*/bin/run-*-vm
           
           for i in */coverage-data; do
             ensureDir $out/coverage-data
@@ -103,6 +122,17 @@ rec {
       # Call the test script with the computed nodes.
       (if builtins.isFunction t.testScript then t.testScript { inherit (vms) nodes; } else t.testScript);
     report = makeReport test;
+
+    # Generate a convenience wrapper for running the test driver
+    # interactively with the specified network.
+    driver = runCommand "nixos-test-driver" { buildInputs = [ makeWrapper]; }
+      ''
+        mkdir -p $out/bin
+        ln -s ${vms}/bin/* $out/bin/
+        ln -s ${testDriver}/bin/* $out/bin/
+        wrapProgram $out/bin/nixos-test-driver \
+          --add-flags "${vms}/vms/*/bin/run-*-vm"
+      ''; # "
   };
 
   runInMachine =
@@ -140,7 +170,7 @@ rec {
         export PATH=${qemu_kvm}/bin:${coreutils}/bin
         cp ${./test-driver/Machine.pm} Machine.pm
         export tests='${testscript}'
-        ${perl}/bin/perl ${./test-driver/test-driver.pl} ${vms}/vms/*/bin/run-*-vm
+        ${testDriver}/bin/nixos-test-driver ${vms}/vms/*/bin/run-*-vm
       ''; # */
 
     in