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Troubleshooting

NameError: uninitialized constant MyModule::MyModelName​

Try with full namespacing ::SomeModule::MyModule::MyModelName.

Debug Knapsack Pro on your development environment/machine​

Regular Mode​

To reproduce what Knapsack Pro executed on a specific CI node, check out the same branch and run:

KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC=MY_TOKEN \
KNAPSACK_PRO_CI_NODE_INDEX=MY_INDEX \
KNAPSACK_PRO_CI_NODE_TOTAL=MY_TOTAL \
KNAPSACK_PRO_BRANCH=MY_BRANCH \
KNAPSACK_PRO_COMMIT_HASH=MY_COMMIT \
KNAPSACK_PRO_CI_NODE_BUILD_ID=MY_BUILD_ID \
bundle exec rake "knapsack_pro:rspec[--seed MY_SEED]"

KNAPSACK_PRO_CI_NODE_BUILD_ID must be the same as the CI build you are trying to reproduce (if it helps, take a look at what Knapsack Pro uses as node_build_id for your CI provider).

You can also run the same subset of tests without Knapsack Pro: in the logs, find the command that Knapsack Pro used to invoke the test runner:

rspec --default-path spec "spec/models/user_spec.rb" "spec/models/comment_spec.rb"

Queue Mode​

To reproduce what Knapsack Pro executed on a specific CI node, check out the same branch and run:

KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC=MY_TOKEN \
KNAPSACK_PRO_CI_NODE_INDEX=MY_INDEX \
KNAPSACK_PRO_CI_NODE_TOTAL=MY_TOTAL \
KNAPSACK_PRO_BRANCH=MY_BRANCH \
KNAPSACK_PRO_COMMIT_HASH=MY_COMMIT \
KNAPSACK_PRO_CI_NODE_BUILD_ID=MY_BUILD_ID \
KNAPSACK_PRO_FIXED_QUEUE_SPLIT=true \
bundle exec rake "knapsack_pro:queue:rspec[--seed MY_SEED]"

KNAPSACK_PRO_CI_NODE_BUILD_ID must be the same as the CI build you are trying to reproduce (if it helps, take a look at what Knapsack Pro uses as node_build_id for your CI provider).

You can also run the same subset of tests without Knapsack Pro: in the logs, find the command that Knapsack Pro used to invoke the test runner.

You will find multiple commands to reproduce each batch:

[knapsack_pro] To retry the last batch of tests fetched from the API Queue, please run the following command on your machine:
[knapsack_pro] bundle exec rspec --format documentation --format RspecJunitFormatter --out tmp/rspec.xml --default-path spec --seed 24098 "spec/features/dashboard/billing/subscription_error_path_1_spec.rb[1:1:2:1:1:1]"

Or a single command at the end to execute all the batches the CI node executed:

[knapsack_pro] To retry all the tests assigned to this CI node, please run the following command on your machine:
[knapsack_pro] bundle exec rspec --format documentation --format RspecJunitFormatter --out tmp/rspec.xml --default-path spec --seed 24098 "spec/features/dashboard/billing/subscription_error_path_1_spec.rb[1:1:2:1:1:1]" "spec/features/dashboard/builds/build_distribution_for_build_spec.rb[1:1:1:10:2:1]" "spec/features/dashboard/builds/build_distribution_for_build_spec.rb[1:1:2:1]" "spec/features/dashboard/admin_statistics_spec.rb[1:6:1:1]" "spec/features/dashboard/identity_providers_spec.rb[1:6:1]" "spec/features/dashboard/onboarding_spec.rb[1:2:1:1:1]"

Knapsack Pro hangs​

Some users reported frozen CI nodes with:

  • Test runners producing too much output (e.g., Codeship and Queue Mode): reduce it with KNAPSACK_PRO_LOG_LEVEL=warn

  • Test runners producing no output: make sure to use a formatter (like RSpec's --format progress)

  • Timecop (e.g., Travis): ensure Timecop.return is executed after all examples

    # spec/spec_helper.rb

    RSpec.configure do |c|
      c.after(:all) do
        Timecop.return
      end
    end

  • Chrome 83+ prevents downloads in sandboxed iframes: add an allow-downloads keyword in the sandbox attribute list

  • Tests freeze and CI node timeouts (the Ruby process is killed by a CI provider). Add the following script to spec_helper.rb. Thanks to that, you will see the backtrace showing what code line causes the hanging problem. Backtrace is visible only if the Ruby process got kill with USR1 signal. Learn more from this GitHub issue.

    # source https://github.com/rspec/rspec-rails/issues/1353#issuecomment-93173691
    puts "Process pid: #{Process.pid}"

    trap 'USR1' do
      threads = Thread.list

      puts
      puts "=" * 80
      puts "Received USR1 signal; printing all #{threads.count} thread backtraces."

      threads.each do |thr|
        description = thr == Thread.main ? "Main thread" : thr.inspect
        puts
        puts "#{description} backtrace: "
        puts thr.backtrace.join("\n")
      end

      puts "=" * 80
    end

    If the CI provider does not kill the frozen process, you can do it by running the below command in the terminal (when you are ssh-ed into the CI node):

    kill -USR1 <process pid>

Knapsack Pro does not work on a forked repository​

caution

Make sure your Knapsack Pro API token is set up as a secret in your CI (not hardcoded in the repository) to avoid leaking it.

Since the token won't be available on forked CI builds, you can use a script to run:

Create bin/knapsack_pro_tests, make it executable chmod u+x, and use it on CI to run your tests:

#!/bin/bash

if [ "$KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC" = "" ]; then
  KNAPSACK_PRO_ENDPOINT=https://api-disabled-for-fork.knapsackpro.com \
  KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC=disabled-for-fork \
  KNAPSACK_PRO_MAX_REQUEST_RETRIES=0 \
  KNAPSACK_PRO_CI_NODE_RETRY_COUNT=0 \
  bundle exec rake knapsack_pro:queue:rspec
else
  bundle exec rake knapsack_pro:queue:rspec
fi

Error commit_hash parameter is required​

Knapsack Pro takes KNAPSACK_PRO_COMMIT_HASH and KNAPSACK_PRO_BRANCH from the CI environment (see supported CIs). If your CI is not supported you may see the following error:

ERROR -- : [knapsack_pro] {"errors"=>[{"commit_hash"=>["parameter is required"]}]}

In such a case, you have two options:

LoadError: cannot load such file -- spec_helper​

If you are using a complex KNAPSACK_PRO_TEST_FILE_PATTERN, Knapsack Pro could have problems finding the directory containing the spec_helper.rb file. Please set KNAPSACK_PRO_TEST_DIR.

CI builds fail with Test::Unit but all tests passed​

Please ensure you are using Test::Unit only and not loading minitest too.

Tests hitting external APIs fail​

Most likely, you have global shared state between your tests.

For example, you may have a hook that deletes Stripe data while a parallel CI node is testing the Stripe integration:

before(:each) do
  Stripe::Subscription.all.each { |subscription| subscription.delete }
  Stripe::Customer.all.each { |customer| customer.delete }
end

You can fix it by either:

  • Using a gem like VCR to record/replay your HTTP interactions
  • Write your tests so that they can run in parallel (e.g., each test creates/deletes its own Stripe data)

OpenSSL::SSL::SSLError​

VCR or WebMock may trigger the following error when Knapsack Pro interacts with the Knapsack Pro API:

OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=error: tlsv1 alert internal error

Make sure to follow the steps to configure VCR/WebMock.

ActiveRecord::SubclassNotFound​

If files are changing during a tests run, you may get the following error:

ActiveRecord::SubclassNotFound:
Invalid single-table inheritance type: AuthenticationProviders::AnAuthenticationProvider is not a subclass of AuthenticationProvider

Please make sure classes are loaded once in the test environment:

# environments/test.rb

config.eager_load = true

Adding parallel CI nodes/jobs makes test slower​

You can verify if the tests are getting slower on your Knapsack Pro dashboard:

  • Execution times of your CI builds are increasing: Recorded CI builds > Show (build) > Test Files > Total execution time
  • Individual test stats are trending up: Statistics of test files history > Stats (test file) > History of the test file (chart)

Here are the most common reasons:

  • CI nodes share resources (CPU/RAM/IO)
  • Tests are accessing the same resource (e.g., Stripe sandbox, database)
  • Your CI gives you a limited pool of parallel CI nodes (and runs the rest serially)

Some tests were skipped in Regular Mode​

There is an unlikely scenario where some CI nodes may start in Fallback Mode but others in Regular Mode resulting in some tests being skipped. Our recommendations are either

FactoryBot/FactoryGirl raises in Queue Mode​

  • Use the knapsack_pro binary:

    bundle exec knapsack_pro queue:rspec

  • Avoid implicit associations:

    # ⛔️ Bad
    FactoryBot.define do
      factory :assignment do
        task
      end
    end

    # ✅ Good
    FactoryBot.define do
      factory :assignment do
        association :task
      end
    end

One CI node run the test suite again in Queue Mode​

Most likely, that CI node started when all the others finished running and initialized a new queue.

You have a couple of options:

Rake tasks under tests are run more than once in Queue Mode​

Make sure the Rake task is loaded once for each test example in the spec file:

class DummyOutput
  class << self
    attr_accessor :count
  end
end

namespace :dummy do
  task do_something_once: :environment do
    DummyOutput.count ||= 0
    DummyOutput.count += 1
    puts "Count: #{DummyOutput.count}"
  end
end

Tests distribution is unbalanced in Queue Mode​

Please consider: