Test driver: exit when all VMs have exited rather than sleeping forever

lib/test-driver/test-driver.pl

@@ -68,6 +68,14 @@ sub startAll {
 }
 
 
+# Wait until all VMs have terminated.
+sub joinAll {
+    $log->nest("waiting for all VMs to finish", sub {
+        $_->waitForShutdown foreach values %vms;
+    });
+}
+
+
 # In interactive tests, this allows the non-interactive test script to
 # be executed conveniently.
 sub testScript {

lib/testing.nix

@@ -157,7 +157,7 @@ rec {
         ln -s ${testDriver}/bin/nixos-test-driver $out/bin/nixos-run-vms
         wrapProgram $out/bin/nixos-run-vms \
           --add-flags "$vms" \
-          --set tests '"startAll; sleep 1e9;"' \
+          --set tests '"startAll; joinAll;"' \
           --set VLANS '"${toString vlans}"'
       ''; # "