Deprecate them in a way that doesn't break reactor installation

installReactor and deprecatedModuleAttribute have a fight :/

src/twisted/internet/__init__.py

@@ -10,29 +10,3 @@
 to use the same code for different loops, from Twisted's basic, yet portable,
 select-based loop to the loops of various GUI toolkits like GTK+ or Tk.
 """
-
-from twisted.python.deprecate import deprecatedModuleAttribute
-from twisted.python.versions import Version
-
-deprecatedModuleAttribute(
-    Version("Twisted", "NEXT", 0, 0),
-    "Please use twisted.internet.gireactor instead.",
-    "twisted.internet",
-    "gtk2reactor",
-)
-
-deprecatedModuleAttribute(
-    Version("Twisted", "NEXT", 0, 0),
-    "Please use twisted.internet.gireactor instead.",
-    "twisted.internet",
-    "gtk3reactor",
-)
-
-deprecatedModuleAttribute(
-    Version("Twisted", "NEXT", 0, 0),
-    "Please use twisted.internet.gireactor instead.",
-    "twisted.internet",
-    "glib2reactor",
-)
-
-del Version, deprecatedModuleAttribute

src/twisted/internet/_deprecate.py

@@ -0,0 +1,23 @@
+"""
+Support similar deprecation of several reactors.
+"""
+
+import warnings
+
+from twisted.python.deprecate import DEPRECATION_WARNING_FORMAT
+from incremental import Version, getVersionString
+
+def deprecatedGnomeReactor(name: str, version: Version) -> None:
+    """
+    Emit a deprecation warning about a gnome-related reactor.
+
+    @param name: The name of the reactor.  For example, C{"gtk2reactor"}.
+
+    @param version: The version in which the deprecation was introduced.
+    """
+    stem = DEPRECATION_WARNING_FORMAT % {
+        "fqpn": "twisted.internet." + name,
+        "version": getVersionString(version),
+    }
+    msg = stem + ".  Please use twisted.internet.gireactor instead."
+    warnings.warn(msg, category=DeprecationWarning)

src/twisted/internet/glib2reactor.py

@@ -16,6 +16,12 @@
 intended to be called directly.
 """
 
+from incremental import Version
+
+from ._deprecate import deprecatedGnomeReactor
+
+deprecatedGnomeReactor("glib2reactor", Version("Twisted", "NEXT", 0, 0))
+
 from twisted.internet import gtk2reactor
 
 

src/twisted/internet/gtk2reactor.py

@@ -16,6 +16,12 @@
 intended to be called directly.
 """
 
+from incremental import Version
+
+from ._deprecate import deprecatedGnomeReactor
+
+deprecatedGnomeReactor("gtk2reactor", Version("Twisted", "NEXT", 0, 0))
+
 # System Imports
 import sys
 

src/twisted/internet/gtk3reactor.py

@@ -6,6 +6,12 @@
 See that module instead.
 """
 
+from incremental import Version
+
+from ._deprecate import deprecatedGnomeReactor
+
+deprecatedGnomeReactor("gtk3reactor", Version("Twisted", "NEXT", 0, 0))
+
 from twisted.internet import gireactor
 
 Gtk3Reactor = gireactor.GIReactor