Enforce pip's legacy-resolver

Change-Id: Id0b97782db354cfa66656746ee03f102b5c4d6e3
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tox.ini b/tox.ini
index d166faf0..d2d67009 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,7 +9,7 @@ deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/master/upper-constraints.txt}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
-install_command = pip install {opts} {packages}
+install_command = pip install --use-deprecated=legacy-resolver {opts} {packages}
 commands =
   pytest \
     --junit-xml=junit.xml \