merge.feature git commit failure: "Please tell me who you are"

I tried to test the merge.feature, and got:

    hub $ RUBYLIB=lib cucumber -f progress -t ~@wip features/merge.feature
    .......F----....F--............

    (::) failed steps (::)

    command "git commit --quiet -m '' --allow-empty --allow-empty-message --author 'Hub <hub@test.local>'" exited with status 128:
      *** Please tell me who you are.

      Run

        git config --global user.email "you@example.com"
        git config --global user.name "Your Name"

      to set your account's default identity.
      Omit --global to set the identity only in this repository.

      fatal: empty ident name (for <wking@tremily.us>) not allowed (RSpec::Expectations::ExpectationNotMetError)
    ./features/support/env.rb:125:in `run_silent'
    ./features/support/env.rb:123:in `run_silent'
    ./features/support/env.rb:133:in `empty_commit'
    ./features/steps.rb:54:in `/^there is a commit named "([^"]+)"$/'
    features/merge.feature:19:in `And there is a commit named "jfirebaugh/hub_merge"'

    command "git commit --quiet -m '' --allow-empty --allow-empty-message --author 'Hub <hub@test.local>'" exited with status 128:
      *** Please tell me who you are.

      Run

        git config --global user.email "you@example.com"
        git config --global user.name "Your Name"

      to set your account's default identity.
      Omit --global to set the identity only in this repository.

      fatal: empty ident name (for <wking@tremily.us>) not allowed (RSpec::Expectations::ExpectationNotMetError)
    ./features/support/env.rb:125:in `run_silent'
    ./features/support/env.rb:123:in `run_silent'
    ./features/support/env.rb:133:in `empty_commit'
    ./features/steps.rb:54:in `/^there is a commit named "([^"]+)"$/'
    features/merge.feature:42:in `And there is a commit named "jfirebaugh/hub_merge"'

    Failing Scenarios:
    cucumber features/merge.feature:7 # Scenario: Merge pull request
    cucumber features/merge.feature:30 # Scenario: Merge pull request

    4 scenarios (2 failed, 2 passed)
    28 steps (2 failed, 6 skipped, 20 passed)
    0m7.610s

I expect the problem is due to the unspecified contributor, and recent versions of Git may have tightened their checking (I'm running Git 1.8.0).