From 70b62fbb913401eab7a109b6a434ceae43acae9d Mon Sep 17 00:00:00 2001
From: Graeme Watt <Graeme.Watt@durham.ac.uk>
Date: Fri, 12 Jun 2020 17:15:16 +0100
Subject: [PATCH] travis: use 'pip install --ignore-installed --upgrade' to fix
 build

---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index a9e0d10..2c8598d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -44,7 +44,7 @@ before_install:
   - "travis_retry pip install --upgrade pip setuptools wheel coveralls"
 
 install:
-  - "travis_retry pip install -e .[tests]"
+  - "travis_retry pip install --ignore-installed --upgrade -e .[tests]"
 
 script:
   - "pytest testsuite"