properly handle subprojects

flake.nix

@@ -1,5 +1,5 @@
 {
-  description = "project with vendored meson subprojects";
+  description = "mu and mu4e email package for emacs";
 
   inputs = { nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable"; };
 
@@ -7,8 +7,9 @@
     let
       system = "x86_64-linux";
       pkgs = import nixpkgs { inherit system; };
+      lib = pkgs.lib;
 
-      # One entry per .wrap file. `hash`/`patchHash` are the
+      # One entry per .wrap file. `sha256`/patch `sha256` are the
       # source_hash/patch_hash values from the .wrap, as-is (hex sha256 --
       # Nix's `sha256 =` attr accepts hex directly).
       subprojects = {
@@ -68,28 +69,34 @@
       # Build the shell commands that stage each subproject's source (and,
       # if present, unzip its wrapdb "patch" overlay on top) into
       # subprojects/<dir>, exactly like `meson subprojects download` would.
-      stageSubprojects = pkgs.lib.concatStrings (pkgs.lib.mapAttrsToList
+      stageSubprojects = lib.concatStrings (lib.mapAttrsToList
         (name: sp: ''
           mkdir -p "subprojects/${sp.dir}"
           tar xf ${sp.src} -C subprojects --strip-components=0
-          ${pkgs.lib.optionalString (sp ? patch) ''
+          ${lib.optionalString (sp ? patch) ''
             unzip -o -q ${sp.patch} -d "subprojects/${sp.dir}"
           ''}
         '') subprojects);
     in {
-      packages.${system}.default = pkgs.stdenv.mkDerivation {
-        name = "myproject";
+      packages.${system}.default =
+        with pkgs;
+        stdenv.mkDerivation {
+          name = "mu4e";
           src = self;
 
-        nativeBuildInputs = with pkgs; [
+          nativeBuildInputs = [
             pkg-config
             meson
             ninja
-          unzip
+            texinfo
+            emacs
             python3
+            cmake
+            cld2
+            unzip
           ];
 
-        buildInputs = [ ];
+          buildInputs = [ glib gmime3 xapian ];
 
           postPatch = stageSubprojects + ''
             # Scripts vendored via fetchurl (e.g. CLI11's scripts/ExtractVersion.py)
@@ -100,8 +107,50 @@
           '';
 
           mesonFlags = [
-          "--wrap-mode=nodownload"
+            # "--debug"
+            "-Dscm=disabled"
+            "-Dreadline=disabled"
+            "-Demacs=${emacs}/bin/emacs"
+            # CLI11's own meson.build pulls in a catch2 subproject for its
+            # test suite. We only consume CLI11 as a library, so disable its
+            # tests option to avoid needing to vendor catch2 as well.
+            "-Dcli11:tests=disabled"
           ];
+
+          # preConfigure = ''
+          #   echo "=== DEBUG: Environment before meson configure ==="
+          #   echo "PWD: $(pwd)"
+          #   echo "Python version:"
+          #   python3 --version || echo "python3 not available"
+          #   echo "Python path:"
+          #   #which python3 || echo "python3 not in PATH"
+          #   echo "PATH: $PATH"
+          #   echo "Meson version:"
+          #   meson --version
+          #   echo "Available files in current directory:"
+          #   ls -la
+          #   echo "Checking for Python scripts:"
+          #   find . -name "*.py" -type f | head -10
+          #   echo "=============================================="
+          # '';
+
+          meta = with lib; {
+            description = "Email indexer and Emacs client (mu4e)";
+            longDescription = ''
+              mu is a tool for dealing with email messages stored in the
+              Maildir-format. mu's purpose in life is to help you to quickly find the
+              messages you need; in addition, it allows you to view messages, extract
+              attachments, create new maildirs, and so on.
+
+              mu4e is an Emacs-based e-mail client that uses mu as its back-end.
+            '';
+            license = licenses.gpl3Plus;
+            homepage = "https://www.djcbsoftware.nl/code/mu/";
+            changelog = "https://github.com/djcb/mu/blob/v${version}/NEWS.org";
+            maintainers = with maintainers; [ antono chvp peterhoeg ];
+            platforms = platforms.unix;
+            mainProgram = "mu";
+          };
         };
     };
 }