The focus flag in rspec is not considered when running spec through guard. It works when running directly with rspec.
See also comments on the rspec project:
Not sure that's related to guard-rspec, when you say it works when running directly with rspec you launch it via rake spec ? Have you try with bundle exec rspec spec/... (it's the way guard-rspec launch it)?
bundle exec rspec spec/...
As a workaround you can add --tag focus in your .rspec file.
Focus flags works when I launch it with bundle exec rspec spec/.. as well as rake spec. The workaround with --tag focus works as well.
bundle exec rspec spec/..
Discussed here too: sporkrb/spork#166
I moved the rspec issue to rspec/rspec-core#554.
I'm closing this issue too here.