don't detect executable file for reloader

CHANGES.rst

@@ -19,6 +19,11 @@ Unreleased
     reloader to fail. :issue:`1607`
 -   Work around an issue where the reloader couldn't introspect a
     setuptools script installed as an egg. :issue:`1600`
+-   The reloader will use ``sys.executable`` even if the script is
+    marked executable, reverting a behavior intended for NixOS
+    introduced in 0.15. The reloader should no longer cause
+    ``OSError: [Errno 8] Exec format error``. :issue:`1482`,
+    :issue:`1580`
 -   ``SharedDataMiddleware`` safely handles paths with Windows drive
     names. :issue:`1589`
 

src/werkzeug/_reloader.py

@@ -61,11 +61,8 @@ def _find_observable_paths(extra_files=None):
 
 
 def _get_args_for_reloading():
-    """Returns the executable. This contains a workaround for windows
-    if the executable is incorrectly reported to not have the .exe
-    extension which can cause bugs on reloading.  This also contains
-    a workaround for linux where the file is executable (possibly with
-    a program other than python)
+    """Determine how the script was executed, and return the args needed
+    to execute it again in a new process.
     """
     rv = [sys.executable]
     py_script = sys.argv[0]
@@ -91,11 +88,6 @@ def _get_args_for_reloading():
             ):
                 rv.pop(0)
 
-        elif os.path.isfile(py_script) and os.access(py_script, os.X_OK):
-            # The file is marked as executable. Nix adds a wrapper that
-            # shouldn't be called with the Python executable.
-            rv.pop(0)
-
         rv.append(py_script)
     else:
         # Executed a module, like "python -m werkzeug.serving".