Some of the environment variables have changed as devstack defaults
have changed. So look for the older env variables first and try the
newer ones later.
At a minimum you need the following for v3 authentication which is
the default with latest devstack. If you miss the Tenant information
then the token issued will be a unscoped token (and will not have any
service catalog information).
OS_AUTH_URL=http://192.168.0.42/identity
OS_REGION_NAME=RegionOne
OS_USERNAME=demo
OS_PASSWORD=supersecret
OS_TENANT_NAME=demo
OS_USER_DOMAIN_ID=default