Add recommended workaround for resolver issues (pypa/pip#9143). Fixes #273.

jaraco · jaraco · commit c769ba8fae24 · 2021-01-10T14:13:38.000-05:00
diff --git a/tox.ini b/tox.ini
@@ -12,6 +12,10 @@ commands =
 	pytest {posargs}
 usedevelop = True
 extras = testing
+setenv =
+	# workaround pypa/pip#9143
+	PIP_USE_DEPRECATED=legacy-resolver
+
 
 [testenv:docs]
 extras =
