Merge pull request #46777 from erikarvstedt/docs

Improve docs

nixos/doc/manual/development/running-nixos-tests-interactively.xml

@@ -19,6 +19,7 @@ starting VDE switch for network 1
 > startAll
 > testScript
 > $machine->succeed("touch /tmp/foo")
+> print($machine->succeed("pwd"), "\n") # Show stdout of command
 </screen>
   The function <command>testScript</command> executes the entire test script
   and drops you back into the test driver command line upon its completion.
@@ -33,8 +34,11 @@ $ nix-build nixos/tests/login.nix -A driver
 $ ./result/bin/nixos-run-vms
 </screen>
   The script <command>nixos-run-vms</command> starts the virtual machines
-  defined by test. The root file system of the VMs is created on the fly and
-  kept across VM restarts in
-  <filename>./</filename><varname>hostname</varname><filename>.qcow2</filename>.
+  defined by test.
+ </para>
+
+ <para>
+  The machine state is kept across VM restarts in
+  <filename>/tmp/vm-state-</filename><varname>machinename</varname>.
  </para>
 </section>

nixos/doc/manual/development/writing-nixos-tests.xml

@@ -108,7 +108,7 @@ xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/virtualis
 <programlisting>
 $machine->start;
 $machine->waitForUnit("default.target");
-$machine->succeed("uname") =~ /Linux/;
+die unless $machine->succeed("uname") =~ /Linux/;
 </programlisting>
   The first line is actually unnecessary; machines are implicitly started when
   you first execute an action on them (such as <literal>waitForUnit</literal>

nixos/modules/services/x11/display-managers/default.nix

@@ -266,7 +266,7 @@ in
           session.  Each session script can set the
           <varname>waitPID</varname> shell variable to make this script
           wait until the end of the user session.  Each script is used
-          to define either a windows manager or a desktop manager.  These
+          to define either a window manager or a desktop manager.  These
           can be differentiated by setting the attribute
           <varname>manage</varname> either to <literal>"window"</literal>
           or <literal>"desktop"</literal>.