Minitest loads *slower* than RSpec?

benchmark.rb

require "benchmark/ips"

File.write "minitest_test.rb", <<-EOS
require "minitest/autorun"
require "minitest/pride"

class MintestTest < Minitest::Test
  def test_foo
    assert true
  end
end
EOS

File.write "rspec_spec.rb", <<-EOS
require "rspec/autorun"

RSpec.describe "RSpec" do
  it "foo" do
    expect(true).to eq true
  end
end
EOS

Benchmark.ips do |x|
  x.config(time: 10)
  x.report("rspec")    { `ruby rspec_spec.rb` }
  x.report("minitest") { `ruby minitest_test.rb` }
  x.compare!
end

# Calculating -------------------------------------
#                rspec     1.000  i/100ms
#             minitest     1.000  i/100ms
# -------------------------------------------------
#                rspec      4.545  (± 0.0%) i/s -     46.000 
#             minitest      3.951  (± 0.0%) i/s -     40.000 
# 
# Comparison:
#                rspec:        4.5 i/s
#             minitest:        4.0 i/s - 1.15x slower

In my fork I've rewritten your benchmark: https://gist.github.com/mislav/8ae7ca40feb7c967ef32#file-readme-md

Turns out there isn't much of a difference. Startup times of these test libraries don't matter anyway; so based on just that it's not really fair to say "X is faster than Y".