nixpkgs/pkgs/by-name/me/melos/add-generic-main.patch

diff --git a/bin/melos.dart b/bin/melos.dart
index 2476436..bd79fad 100644
--- a/packages/melos/bin/melos.dart
+++ b/packages/melos/bin/melos.dart
@@ -1,11 +1,72 @@
 import 'package:cli_launcher/cli_launcher.dart';
 import 'package:melos/src/command_runner.dart';
+import 'dart:io';
+import 'package:yaml/yaml.dart';
+import 'package:path/path.dart' as path;
 
-Future<void> main(List<String> arguments) async => launchExecutable(
-  arguments,
-  LaunchConfig(
-    name: ExecutableName('melos'),
-    launchFromSelf: false,
-    entrypoint: melosEntryPoint,
-  ),
-);
+final ExecutableName executableName = ExecutableName('melos');
+
+Future<void> main(List<String> arguments) async {
+  final workspaceRoot = _findLocalInstallation(Directory.current);
+
+  if (workspaceRoot == null) {
+    print("Error: Could not find your work  ");
+    return;
+  }
+
+  melosEntryPoint(
+    arguments,
+    LaunchContext(
+      directory: Directory.current,
+      localInstallation: ExecutableInstallation(
+        name: executableName,
+        isSelf: false,
+        packageRoot: workspaceRoot,
+      ),
+    ),
+  );
+}
+
+// Stolen then simplified from https://github.com/blaugold/cli_launcher/blob/dcdf11c42b77ddc8e38e7e2445c8cff9b55658ec/lib/cli_launcher.dart#L249
+Directory? _findLocalInstallation(
+  Directory start,
+) {
+  if (path.equals(start.path, start.parent.path)) {
+    return null;
+  }
+
+  final pubspecFile = File(path.join(start.path, 'pubspec.yaml'));
+  if (pubspecFile.existsSync()) {
+    final pubspecString = pubspecFile.readAsStringSync();
+    String? name;
+    YamlMap? dependencies;
+    YamlMap? devDependencies;
+
+    try {
+      final pubspecYaml = loadYamlDocument(
+        pubspecString,
+        sourceUrl: pubspecFile.uri,
+      );
+      final pubspec = pubspecYaml.contents as YamlMap;
+      name = pubspec['name'] as String?;
+      dependencies = pubspec['dependencies'] as YamlMap?;
+      devDependencies = pubspec['dev_dependencies'] as YamlMap?;
+    } catch (error, stackTrace) {
+      throw StateError(
+        'Could not parse pubspec.yaml at ${start.path}.\n$error\n$stackTrace',
+      );
+    }
+
+    final isSelf = name == executableName.package;
+
+    if ((isSelf) ||
+        (dependencies != null &&
+            dependencies.containsKey(executableName.package)) ||
+        (devDependencies != null &&
+            devDependencies.containsKey(executableName.package))) {
+      return start;
+    }
+  }
+
+  return _findLocalInstallation(start.parent);
+}