flake: patch using the target system instead of the host

flake.nix

@@ -43,10 +43,12 @@
 
       evalHost = { name, local, target }:
         let
-          # XXX: we'd prefer to use `nixosSystem = (nixpkgsCompiledBy local).nixos`
+          # XXX: we'd prefer to use `nixosSystem = (nixpkgsCompiledBy target).nixos`
           # but it doesn't propagate config to the underlying pkgs, meaning it doesn't let you use
           # non-free packages even after setting nixpkgs.allowUnfree.
-          nixosSystem = import ((nixpkgsCompiledBy local).path + "/nixos/lib/eval-config.nix");
+          # XXX: patch using the target -- not local -- otherwise the target will
+          # need to emulate the host in order to rebuild!
+          nixosSystem = import ((nixpkgsCompiledBy target).path + "/nixos/lib/eval-config.nix");
         in
           (nixosSystem {
             # we use pkgs built for and *by* the target, i.e. emulation, by default.

hosts/common/cross.nix

@@ -1,5 +1,12 @@
-{ ... }:
+{ config, ... }:
 
+let
+  mkCrossFrom = localSystem: pkgs: import pkgs.path {
+    inherit localSystem;
+    crossSystem = pkgs.stdenv.hostPlatform.system;
+    inherit (config.nixpkgs) config overlays;
+  };
+in
 {
   # the configuration of which specific package set `pkgs.cross` refers to happens elsewhere;
   # here we just define them all.
@@ -8,8 +15,8 @@
       # non-emulated packages build *from* local *for* target.
       # for large packages like the linux kernel which are expensive to build under emulation,
       # the config can explicitly pull such packages from `pkgs.cross` to do more efficient cross-compilation.
-      crossFrom."x86_64-linux" = (prev.forceSystem "x86_64-linux" null).appendOverlays next.overlays;
-      crossFrom."aarch64-linux" = (prev.forceSystem "aarch64-linux" null).appendOverlays next.overlays;
+      crossFrom."x86_64-linux" = mkCrossFrom "x86_64-linux" next;
+      crossFrom."aarch64-linux" = mkCrossFrom "aarch64-linux" next;
     })
   ];
 }

hosts/common/feeds.nix

@@ -41,6 +41,8 @@ let
       );
     } // lib.optionalAttrs (raw.is_podcast or false) {
       format = "podcast";
+    } // lib.optionalAttrs (raw.title or "" != "") {
+      title = lib.mkDefault raw.title;
     };
 
   podcasts = [

hosts/moby/kernel.nix

@@ -125,6 +125,9 @@ in
         # aarch64-unknown-linux-gnu-gcc: error: unrecognized command line option '-mfpu=neon'
         # make[3]: *** [../scripts/Makefile.build:289: drivers/video/fbdev/sun5i-eink-neon.o] Error 1
         FB_SUN5I_EINK = no;
+        # used by the pinephone pro, but fails to compile with:
+        # ../drivers/media/i2c/ov8858.c:1834:27: error: implicit declaration of function 'compat_ptr'
+        VIDEO_OV8858 = no;
       })
     ))
   ];

modules/feeds.nix

@@ -16,6 +16,10 @@ let
         type = types.enum [ "text" "image" "podcast" ];
         default = "text";
       };
+      title = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+      };
       url = mkOption {
         type = types.str;
         description = ''

modules/lib/feeds.nix

@@ -12,8 +12,24 @@ rec {
   # transform a list of feeds into an attrs mapping cat => [ feed0 feed1 ... ]
   partitionByCat = feeds: builtins.groupBy (f: f.cat) feeds;
 
+  xmlTag = tag: close: attrs:
+    let
+      fmt-attrs = builtins.concatStringsSep
+        " "
+        (lib.mapAttrsToList (name: value: ''${lib.escapeXML name}="${lib.escapeXML value}"'') attrs);
+      fmt-close = if close then "/" else "";
+    in
+      ''<${tag} ${fmt-attrs} ${fmt-close}>'';
+
   # represents a single RSS feed.
-  opmlTerminal = feed: ''<outline xmlUrl="${feed.url}" type="rss"/>'';
+  opmlTerminal = feed: xmlTag "outline" true (
+    {
+      xmlUrl = feed.url;
+      type = "rss";
+    } // lib.optionalAttrs (feed.title != null) {
+      title = feed.title;
+    }
+  );
   # a list of RSS feeds.
   opmlTerminals = feeds: lib.concatStringsSep "\n" (builtins.map opmlTerminal feeds);
   # one node which packages some flat grouping of terminals.

pkgs/linux-megous/default.nix

@@ -5,7 +5,7 @@ with lib;
 let
   base = "6.1.0";
   # set to empty if not a release candidate
-  rc = "-rc7";
+  rc = "-rc8";
 in buildLinux (args // rec {
   version = base + rc;
 
@@ -16,9 +16,15 @@ in buildLinux (args // rec {
   extraMeta.branch = versions.majorMinor version;
 
   src = fetchFromGitHub {
+    # HOW TO UPDATE:
+    # - `git fetch` from megous' github.
+    # - there should be some new tag, like `orange-pi-6.1-blah`. use that.
+    # - megi publishes release notes as the most recent commit on any stable branch, so just `git log`.
+    # - orange-pi is listed as the "main integration branch".
+    #   - specific branches like `pp` (pinephone) are dev branches, and probably less stable.
     owner = "megous";
     repo = "linux";
-    rev = "orange-pi-6.1-20221128-1027";
-    hash = "sha256-kEujs4v5rPHPYy4YLyEWHa1Bu0sxoXLgSvmOH9QPWos=";
+    rev = "orange-pi-6.1-20221211-1046";
+    hash = "sha256-TgFXH8bHWHs26rlf7a/zNO9zubFazC8Ie6J1gj4gLgw=";
   };
 } // (args.argsOverride or { }))