actually build a standalone executable (runnable outside of yarn)

flake.nix

@@ -41,6 +41,12 @@
 # - --no-sandbox
 # - --no-zygote   (fixes Zygote could not fork: process_type gpu-process numfds 3 child_pid -1)
 # - --disable-gpu
+#
+#
+# debugging notes
+# `./node_modules/.bin/electron .` is reading `./package.json`.
+#  - dependent on:   "main": "app/main.js"
+#    app/main.js is generated (from app/main.ts, checked into git)
 {
   inputs = {
     nixpkgs.url = "nixpkgs/nixos-unstable";
@@ -142,16 +148,31 @@
           mkdir cache-electron ; rm -rf ~/.cache/electron ; ln -s $(pwd)/cache-electron ~/.cache/electron
           mkdir cache-ms-playwright ; rm -rf ~/.cache/ms-playwright ; ln -s $(pwd)/cache-ms-playwright ~/.cache/ms-playwright
         '';
+
         # run this to clean state, and then build + run Signal in a way which i know WORKS.
         # you should land at the Signal pairing screen at the end of the command.
-        reproducible = with pkgs; writeShellScriptBin "reproducible" ''
+        reproducible0 = with pkgs; writeShellScriptBin "reproducible0" ''
           clean
           link-caches
           yarn install --frozen-lockfile
           yarn generate
           yarn build:esbuild:prod
           patch-interpreter node_modules/electron/dist/electron
-          yarn start
+          # yarn start
+          ./node_modules/.bin/electron .  # equiv to `yarn start`
+        '';
+        reproducible1 = with pkgs; writeShellScriptBin "reproducible1" ''
+          clean
+          link-caches
+          yarn install --frozen-lockfile
+          yarn generate
+          yarn build:esbuild:prod
+          patch-interpreter node_modules/electron/dist/electron
+          # this fails because it tries to also build the deb -- but we don't need that!
+          yarn build:release || true
+          patch-interpreter release/linux-unpacked/signal-desktop
+
+          echo "launch signal with: ./release/linux-unpacked/signal-desktop"
         '';
       in {
         devShells.default = with pkgs; mkShell {
@@ -164,7 +185,8 @@
             link-caches
             patch-interpreter
             patch-signal
-            reproducible
+            reproducible0
+            reproducible1
 
             # yarn
             (yarn.override { nodejs = nodejs_18_15_0; })