Add my analysis. I dumped the command to execute less compiler as follow:
"/opt/stack/horizon/bin/less/lessc /opt/stack/horizon/openstack_dashboard/static/dashboard/less/horizon.less /tmp/tmpNAba42.css"
The return code is 0 but there's an error message printed in the console which make it very wried:
"Fatal Python error: Couldn't create autoTLSkey mapping"
So this might not be caused by LESS installation problem.
Add my analysis. I dumped the command to execute less compiler as follow: opt/stack/ horizon/ bin/less/ lessc /opt/stack/ horizon/ openstack_ dashboard/ static/ dashboard/ less/horizon. less /tmp/tmpNAba42.css"
"/
The return code is 0 but there's an error message printed in the console which make it very wried:
"Fatal Python error: Couldn't create autoTLSkey mapping"
So this might not be caused by LESS installation problem.