Description of problem:
If the user sources ~/overcloudrc.v3, does some CLI commands, then sources ~/stackrc, all CLI commands will fail with:
"Cannot use v2 authentication with domain scope"

Version-Release number of selected component (if applicable):
puddles/OpenStack/10.0-RHEL-7/2017-06-19.1/RH7-RHOS-10.0.repo

How reproducible:
Install director and deploy an overcloud.
source ~/overcloudrc.v3
source ~/stackrc
nova list
ERROR (DiscoveryFailure): Cannot use v2 authentication with domain scope

If at this point you do:
unset OS_USER_DOMAIN_NAME
unset OS_PROJECT_DOMAIN_NAME
nova list
It works.

Steps to Reproduce:
See above.

Actual results:
All CLI commands fail with "Cannot use v2 authentication with domain scope".

Expected results:
CLI commands should work after sourcing the v3 rc followed by sourcing the stackrc.

Additional info:
This can be fixed by adding the following line (taken from overcloudrc) to the beginning of stackrc:

for key in $( set | awk '{FS="="}  /^OS_/ {print $1}' ); do unset $key ; done