From b13b7d803371bca63783b1b687ee232c468283d2 Mon Sep 17 00:00:00 2001
From: Yiyu Zhu <smallzzy@users.noreply.github.com>
Date: Wed, 12 Feb 2020 06:21:04 -0800
Subject: [PATCH] pin virtualenv (#822)

https://github.com/tox-dev/tox/issues/1516
---
 .travis.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index aea3b67d..483164a7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -42,7 +42,7 @@ matrix:
       #    # update: true
       #    packages: python3.7
       before_install:
-        - pip3 install virtualenv
+        - pip3 install virtualenv==16.0.0
         - virtualenv -p python3 ~/venv
         - source ~/venv/bin/activate
 #    - os: windows
@@ -57,7 +57,7 @@ cache: pip
 
 install:
   - pip install future  # needed for `builtins`
-  - sudo pip install tox
+  - pip install tox virtualenv==16.0.0
 
 before_script:
   # rewrite all minimal requirements as strict