TeamCity does not catch failing tests in minitest

Question

I have TeamCity up and running in a mac environment. A trigger is also setup to to run a rake task containing a number of test cases on every git commit. The rake command successfully pulls the code and runs the test cases. The passing test cases are shown correctly in the TeamCity interface, however, the failing test cases do not show up and the build is marked as successful. When I look at the error Build Log, failing tests are shown as errors. The question is why TeamCity is interpreting failing tests as errors and not as actual failing tests?

The assertions are as simple as the following (obvious failure):

test 'simple_test' do
    a = 14
    ssert_equal 341, a
ends

PS: the check box to fail the build upon at least one test fail is turned on in Failure Conditions(i.e. at least one test failed)

Ruby version = 2.2.2,
Rails version = 4.2.1,
TeamCity version =  9.1.1,
Testing framework = minitest,

Here is the build log output

Answer 1

Teamcity is not picking up failed tests because mini-test reporter is not up and running. To fix this, following gems must be present in the Gemfile:

gem "minitest", :group => :test
gem 'minitest-reporters', :group => :test

Also minitest reporter must be called. The best place to call it is test_helper.rb

require 'minitest/reporters'
MiniTest::Reporters.use!