task.py more exception handling compute_extra

Make compute_extra more verbal so we can get a better idea of what is
happening should the function fail.
3 jobs for feature-s/more_verbal_compute_extra in 6 minutes and 4 seconds (queued for 3 seconds)
latest
Status Job ID Name Coverage
  Test Tools
passed #198326
test_tools

00:00:07

 
  Test Unit
passed #198327
web
test_server_unit

00:00:18

 
  Test Functional
passed #198328
docker x86_64
test_server_functional

00:05:39