From dbfcb238dec65f78bfcc1df2243a9a5a41d48a6b Mon Sep 17 00:00:00 2001
From: Itamar Turner-Trauring <itamar@itamarst.org>
Date: Mon, 20 May 2019 10:14:41 -0400
Subject: [PATCH 1/4] Try enabling Python 3.5.2.

---
 .travis.yml | 1 +
 tox.ini     | 1 +
 2 files changed, 2 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index 84c525c..95a1d4f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,7 @@ language: python
 dist: xenial
 python:
   - "3.5"
+  - "3.5.2"
   - "3.6"
   - "3.7"
   - "pypy3"
diff --git a/tox.ini b/tox.ini
index 74f35dc..9954219 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,6 +6,7 @@ envlist = py35-numpy, py36, py37, pypy3,
 [travis]
 python =
        3.5: py35-numpy, py35-twisted-latest
+       3.5.2: py35-numpy
        3.6: py36
        3.7: py37, linters3, sphinx
        pypy3: pypy3

From 07047ac788dd2fc0d93bab072c7408c9c243fc2a Mon Sep 17 00:00:00 2001
From: Itamar Turner-Trauring <itamar@itamarst.org>
Date: Mon, 20 May 2019 10:19:31 -0400
Subject: [PATCH 2/4] Fix for older versions of Python 3.5.

---
 docs/source/news.rst | 4 ++++
 eliot/__init__.py    | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/docs/source/news.rst b/docs/source/news.rst
index f42b06e..17c7b94 100644
--- a/docs/source/news.rst
+++ b/docs/source/news.rst
@@ -4,6 +4,10 @@ What's New
 1.9.0
 ^^^^^
 
+Bug fixes:
+
+* Older versions of Python 3.5, e.g. the 3.5.2 on Ubuntu Xenial, should work again. Fixes #418.
+
 Features:
 
 * If you call ``to_file()/FileDestination()`` with a non-writable file, an
diff --git a/eliot/__init__.py b/eliot/__init__.py
index 8112060..3300d33 100644
--- a/eliot/__init__.py
+++ b/eliot/__init__.py
@@ -6,6 +6,15 @@
 
 # Enable asyncio contextvars support in Python 3.5/3.6:
 if version_info < (3, 7):
+    # On Python 3.5.2 and earlier, some of the necessary attributes aren't exposed:
+    import asyncio
+    if getattr(asyncio, "_get_running_loop", None) is None:
+        from asyncio import events
+        asyncio._get_running_loop = events._get_running_loop
+        asyncio._set_running_loop = events._set_running_loop
+        del events
+    del asyncio
+
     import aiocontextvars
 
     dir(aiocontextvars)  # pacify pyflakes

From c9e51fad9f67e240166aca0366bfc4d690545f62 Mon Sep 17 00:00:00 2001
From: Itamar Turner-Trauring <itamar@itamarst.org>
Date: Mon, 20 May 2019 13:22:31 -0400
Subject: [PATCH 3/4] Break in a more understandable manner on Python 3.5.2 and
 earlier.

---
 docs/source/news.rst |  4 ++--
 eliot/__init__.py    | 15 +++++++--------
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/docs/source/news.rst b/docs/source/news.rst
index 17c7b94..4c64309 100644
--- a/docs/source/news.rst
+++ b/docs/source/news.rst
@@ -4,9 +4,9 @@ What's New
 1.9.0
 ^^^^^
 
-Bug fixes:
+Deprecation:
 
-* Older versions of Python 3.5, e.g. the 3.5.2 on Ubuntu Xenial, should work again. Fixes #418.
+* Python versions older than 3.5.3, e.g. the 3.5.2 on Ubuntu Xenial, don't work with Eliot, so added a more informative error message explaining that. Fixes #418.
 
 Features:
 
diff --git a/eliot/__init__.py b/eliot/__init__.py
index 3300d33..0b9e444 100644
--- a/eliot/__init__.py
+++ b/eliot/__init__.py
@@ -7,14 +7,13 @@
 # Enable asyncio contextvars support in Python 3.5/3.6:
 if version_info < (3, 7):
     # On Python 3.5.2 and earlier, some of the necessary attributes aren't exposed:
-    import asyncio
-    if getattr(asyncio, "_get_running_loop", None) is None:
-        from asyncio import events
-        asyncio._get_running_loop = events._get_running_loop
-        asyncio._set_running_loop = events._set_running_loop
-        del events
-    del asyncio
-
+    if version_info < (3, 5, 3):
+        raise RuntimeError(
+            "This version of Eliot doesn't work on Python 3.5.2 or earlier. "
+            "Either upgrade to a newer version of Python (e.g. on Ubuntu 16.04 "
+            "you can use the deadsnakes PPA to get Python 3.6), or pin Eliot "
+            "to version 1.7."
+        )
     import aiocontextvars
 
     dir(aiocontextvars)  # pacify pyflakes

From 7a7ea92c23f96fbde3c74ede67458d35bcf188ef Mon Sep 17 00:00:00 2001
From: Itamar Turner-Trauring <itamar@itamarst.org>
Date: Mon, 20 May 2019 13:27:06 -0400
Subject: [PATCH 4/4] Disable 3.5.2 testing, since we're not supporting it.

---
 .travis.yml       | 1 -
 eliot/__init__.py | 6 +++---
 tox.ini           | 1 -
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 95a1d4f..84c525c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,6 @@ language: python
 dist: xenial
 python:
   - "3.5"
-  - "3.5.2"
   - "3.6"
   - "3.7"
   - "pypy3"
diff --git a/eliot/__init__.py b/eliot/__init__.py
index 0b9e444..feacde5 100644
--- a/eliot/__init__.py
+++ b/eliot/__init__.py
@@ -10,9 +10,9 @@
     if version_info < (3, 5, 3):
         raise RuntimeError(
             "This version of Eliot doesn't work on Python 3.5.2 or earlier. "
-            "Either upgrade to a newer version of Python (e.g. on Ubuntu 16.04 "
-            "you can use the deadsnakes PPA to get Python 3.6), or pin Eliot "
-            "to version 1.7."
+            "Either upgrade to Python 3.5.3 or later (on Ubuntu 16.04 "
+            "you can use https://launchpad.net/~deadsnakes/+archive/ubuntu/ppa "
+            "to get Python 3.6), or pin Eliot to version 1.7."
         )
     import aiocontextvars
 
diff --git a/tox.ini b/tox.ini
index 9954219..74f35dc 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,7 +6,6 @@ envlist = py35-numpy, py36, py37, pypy3,
 [travis]
 python =
        3.5: py35-numpy, py35-twisted-latest
-       3.5.2: py35-numpy
        3.6: py36
        3.7: py37, linters3, sphinx
        pypy3: pypy3