fix electron path

lib/gui/electron.py

@@ -1,5 +1,6 @@
 import os
 import subprocess
+import sys
 
 from ..utils import get_bundled_dir
 
@@ -10,7 +11,19 @@ app_process = None
 def open_url(url):
     global app
 
-    electron_path = os.path.join(get_bundled_dir("electron"), "out", "inkstitch-linux-x64", "inkstitch-gui")
+    if getattr(sys, 'frozen', None) is not None:
+        electron_path = os.path.join(get_bundled_dir("electron"), "inkstitch-gui")
+    else:
+        # It's a bit trickier to find the electron app in a development environment.
+        base_dir = get_bundled_dir("electron")
+
+        try:
+            package_dir = os.listdir(os.path.join(base_dir, "out"))[0]
+        except (OSError, IndexError):
+            raise Exception("Electron app not found.  Be sure to run 'npm install; npm run package' in %s." % base_dir)
+
+        electron_path = os.path.join(base_dir, "out", package_dir, "inkstitch-gui")
+
     app_process = subprocess.Popen([electron_path, url])
 
     return app_process