```ruby
require 'pry'
require 'rspec/its'


RSpec.configure do |c|
  # Enable 'should' syntax
  c.expect_with(:rspec) { |c| c.syntax = [:should, :expect] }
  c.mock_with(:rspec)   { |c| c.syntax = [:should, :expect] }
  
  # Only run tests marked with iso:true.
  c.filter_run_including iso:true
  c.run_all_when_everything_filtered = true
  
  # Abort after first failure.
  # (Use environment variable for developer preference)
  c.fail_fast = true if ENV['RSPEC_FAIL_FAST']
  
  # Set output formatter and enable color.
  c.formatter = 'Fivemat'
  c.color     = true
end
```

Change spec filter :iso to :focus for compatibility with `fit` method.
user
```ruby
require 'pry'
require 'rspec/its'


RSpec.configure do |c|
  # Enable 'should' syntax
  c.expect_with(:rspec) { |c| c.syntax = [:should, :expect] }
  c.mock_with(:rspec)   { |c| c.syntax = [:should, :expect] }
  
  # Only run tests marked with focus: true.
  c.filter_run_including focus: true
  c.run_all_when_everything_filtered = true
  
  # Abort after first failure.
  # (Use environment variable for developer preference)
  c.fail_fast = true if ENV['RSPEC_FAIL_FAST']
  
  # Set output formatter and enable color.
  c.formatter = 'Fivemat'
  c.color     = true
end
```
assistant