README.md in knapsack_pro-2.0.0 vs README.md in knapsack_pro-2.1.0

@@ -82,10 +82,11 @@
     - [KNAPSACK_PRO_FIXED_QUEUE_SPLIT (remember queue split on retry CI node)](#knapsack_pro_fixed_queue_split-remember-queue-split-on-retry-ci-node)
     - [KNAPSACK_PRO_MODIFY_DEFAULT_RSPEC_FORMATTERS (hide duplicated summary of pending and failed tests)](#knapsack_pro_modify_default_rspec_formatters-hide-duplicated-summary-of-pending-and-failed-tests)
   - [Supported test runners in queue mode](#supported-test-runners-in-queue-mode)
 - [Split test files by test cases](#split-test-files-by-test-cases)
   - [RSpec split test files by test examples (by individual `it`s)](#rspec-split-test-files-by-test-examples-by-individual-its)
+    - [Why I see error: Don't know how to build task 'knapsack_pro:rspec_test_example_detector'?](#why-i-see-error-dont-know-how-to-build-task-knapsack_prorspec_test_example_detector)
   - [How to manually define a list of slow test files to be split by test cases](#how-to-manually-define-a-list-of-slow-test-files-to-be-split-by-test-cases)
 - [Extra configuration for CI server](#extra-configuration-for-ci-server)
   - [Info about ENV variables](#info-about-env-variables)
     - [KNAPSACK_PRO_FIXED_TEST_SUITE_SPLIT (test suite split based on seed)](#knapsack_pro_fixed_test_suite_split-test-suite-split-based-on-seed)
     - [Environment variables for debugging gem](#environment-variables-for-debugging-gem)
@@ -615,9 +616,19 @@
 ```
 KNAPSACK_PRO_RSPEC_SPLIT_BY_TEST_EXAMPLES=true
 ```
 
 Thanks to that your CI build speed can be faster. We recommend using this feature with [Queue Mode](https://youtu.be/hUEB1XDKEFY) to ensure parallel CI nodes finish work at a similar time which gives you the shortest CI build time.
+
+#### Why I see error: Don't know how to build task 'knapsack_pro:rspec_test_example_detector'?
+
+If you will see error like:
+
+```
+Don't know how to build task 'knapsack_pro:rspec_test_example_detector' (See the list of available tasks with `rake --tasks`)
+```
+
+It probably means bundler can't find the rake task. You can try remove default prefix `bundle exec` used by knapsack_pro gem by setting `KNAPSACK_PRO_RSPEC_TEST_EXAMPLE_DETECTOR_PREFIX=""`.
 
 ### How to manually define a list of slow test files to be split by test cases
 
 If you don't want to rely on a list of test files from Knapsack Pro API to determine slow test files that should be split by test cases then you can define your own list of slow test files.