nixos/doc/rl-2211.section.md: changes w.r.t. cross check execution

nixos/doc/manual/from_md/release-notes/rl-2211.section.xml

@@ -13,8 +13,22 @@
     <itemizedlist spacing="compact">
       <listitem>
         <para>
-          Please remove this line when you add the first item since
-          docbook requires the section to be non-empty
+          During cross-compilation, tests are now executed if the test
+          suite can be executed by the build platform. This is the case
+          when doing “native” cross-compilation where the build and host
+          platforms are largely the same, but the nixpkgs’ cross
+          compilation infrastructure is used, e.g.
+          <literal>pkgsStatic</literal> and <literal>pkgsLLVM</literal>.
+          Another possibility is that the build platform is a superset
+          of the host platform, e.g. when cross-compiling from
+          <literal>x86_64-unknown-linux</literal> to
+          <literal>i686-unknown-linux</literal>. The predicate gating
+          test suite execution is the newly added
+          <literal>canExecute</literal> predicate: You can e.g. check if
+          <literal>stdenv.buildPlatform</literal> can execute binaries
+          built for <literal>stdenv.hostPlatform</literal> (i.e.
+          produced by <literal>stdenv.cc</literal>) by evaluating
+          <literal>stdenv.buildPlatform.canExecute stdenv.hostPlatform</literal>.
         </para>
       </listitem>
     </itemizedlist>
@@ -35,8 +49,19 @@
     <itemizedlist spacing="compact">
       <listitem>
         <para>
-          Please remove this line when you add the first item since
-          docbook requires the section to be non-empty
+          The <literal>isCompatible</literal> predicate checking CPU
+          compatibility is no longer exposed by the platform sets
+          generated using <literal>lib.systems.elaborate</literal>. In
+          most cases you will want to use the new
+          <literal>canExecute</literal> predicate instead which also
+          considers the kernel / syscall interface. It is briefly
+          described in the release’s
+          <link linkend="sec-release-22.11-highlights">highlights
+          section</link>.
+          <literal>lib.systems.parse.isCompatible</literal> still
+          exists, but has changed semantically: Architectures with
+          differing endianness modes are <emphasis>no longer considered
+          compatible</emphasis>.
         </para>
       </listitem>
     </itemizedlist>

nixos/doc/manual/release-notes/rl-2211.section.md

@@ -6,7 +6,16 @@ Support is planned until the end of June 2023, handing over to 23.05.
 
 In addition to numerous new and upgraded packages, this release has the following highlights:
 
-- Please remove this line when you add the first item since docbook requires the section to be non-empty
+- During cross-compilation, tests are now executed if the test suite can be executed
+  by the build platform. This is the case when doing “native” cross-compilation
+  where the build and host platforms are largely the same, but the nixpkgs' cross
+  compilation infrastructure is used, e.g. `pkgsStatic` and `pkgsLLVM`. Another
+  possibility is that the build platform is a superset of the host platform, e.g. when
+  cross-compiling from `x86_64-unknown-linux` to `i686-unknown-linux`.
+  The predicate gating test suite execution is the newly added `canExecute`
+  predicate: You can e.g. check if `stdenv.buildPlatform` can execute binaries
+  built for `stdenv.hostPlatform` (i.e. produced by `stdenv.cc`) by evaluating
+  `stdenv.buildPlatform.canExecute stdenv.hostPlatform`.
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
@@ -18,7 +27,14 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 ## Backward Incompatibilities {#sec-release-22.11-incompatibilities}
 
-- Please remove this line when you add the first item since docbook requires the section to be non-empty
+- The `isCompatible` predicate checking CPU compatibility is no longer exposed
+  by the platform sets generated using `lib.systems.elaborate`. In most cases
+  you will want to use the new `canExecute` predicate instead which also
+  considers the kernel / syscall interface. It is briefly described in the
+  release's [highlights section](#sec-release-22.11-highlights).
+  `lib.systems.parse.isCompatible` still exists, but has changed semantically:
+  Architectures with differing endianness modes are *no longer considered compatible*.
+
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
 ## Other Notable Changes {#sec-release-22.11-notable-changes}