From b0fd8742da28c2df2bd20cab9d67b432ce542951 Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Sun, 6 Oct 2019 16:00:54 +0200
Subject: [PATCH] ci: test oldest supported attrs

---
 .travis.yml | 3 ++-
 setup.py    | 2 +-
 tox.ini     | 2 ++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 5de40f3a4..c713a19a1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -49,8 +49,9 @@ jobs:
     # - pytester's LsofFdLeakChecker
     # - TestArgComplete (linux only)
     # - numpy
+    # - old attrs
     # Empty PYTEST_ADDOPTS to run this non-verbose.
-    - env: TOXENV=py37-lsof-numpy-twisted-xdist PYTEST_COVERAGE=1 PYTEST_ADDOPTS=
+    - env: TOXENV=py37-lsof-oldattrs-numpy-twisted-xdist PYTEST_COVERAGE=1 PYTEST_ADDOPTS=
 
     # Specialized factors for py37.
     # Coverage for:
diff --git a/setup.py b/setup.py
index adbafb557..dcf63f6fd 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@ from setuptools import setup
 INSTALL_REQUIRES = [
     "py>=1.5.0",
     "packaging",
-    "attrs>=17.4.0",
+    "attrs>=17.4.0",  # should match oldattrs tox env.
     "more-itertools>=4.0.0",
     "atomicwrites>=1.0",
     'pathlib2>=2.2.0;python_version<"3.6"',
diff --git a/tox.ini b/tox.ini
index e95b011b6..e1b611f58 100644
--- a/tox.ini
+++ b/tox.ini
@@ -41,6 +41,8 @@ setenv =
     xdist: _PYTEST_TOX_POSARGS_XDIST=-n auto
 extras = testing
 deps =
+    oldattrs: attrs==17.4.0
+    oldattrs: hypothesis<=4.38.1
     numpy: numpy
     pexpect: pexpect
     pluggymaster: git+https://github.com/pytest-dev/pluggy.git@master