anchor.diff:        # Now see if we can boot the installation.
         $machine = createMachine({ ${hdFlags} qemuFlags => "${qemuFlags}" });
   
  +      # For example to enter LUKS passphrase
  +      ${preBootCommands}
  +
         # Did /boot get mounted?
         $machine->waitForUnit("local-fs.target");
   
  
positive.code: 
        # Check whether a writable store build works
        $machine = createMachine({ ${hdFlags} qemuFlags => "${qemuFlags}" });
        $machine->waitForUnit("multi-user.target");
        $machine->copyFileFromHost(
            "${ makeConfig { inherit testChannel grubVersion grubDevice grubIdentifier extraConfig; readOnly = false; forceGrubReinstallCount = 2; } }",
  
negative.code:       # And just to be sure, check that the machine still boots after
        # "nixos-rebuild switch".
        $machine = createMachine({ ${hdFlags} qemuFlags => "${qemuFlags}" });
        ${preBootCommands}
        $machine->waitForUnit("network.target");
        $machine->shutdown;
      '';
  
  
    makeInstallerTest = name:
      { createPartitions, preBootCommands ? "", extraConfig ? ""
      , testChannel ? false, grubVersion ? 2, grubDevice ? "/dev/vda"
      , grubIdentifier ? "uuid"
      }:
      makeTest {
        inherit iso;
        name = "installer-" + name;
        nodes = if testChannel then { inherit webserver; } else { };
        testScript = testScriptFun {
          inherit createPartitions preBootCommands testChannel grubVersion
                  grubDevice grubIdentifier extraConfig;
        };
      };
  
  