Ceedling JUnit Test Report fails - undefined method `merge' for nil:NilClass

Question

I need to run ceedling and generate JUnit test reports. I have read the documentation on how to do it here: https://github.com/ThrowTheSwitch/Ceedling/tree/v0.31.1/plugins/junit_tests_report. I have added the necessary options in the project.yml file.

But still it fails. I receive the following issue:

--------------------
OVERALL TEST SUMMARY
--------------------
TESTED:  124
PASSED:  124
FAILED:    0
IGNORED:   0

Exception raised in plugin: junit_tests_report, in method post_build
Traceback (most recent call last):
    16: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/rakefile.rb:78:in `block in <top (required)>'
    15: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/plugin_manager.rb:85:in `post_build'
    14: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/plugin_manager.rb:97:in `execute_plugins'
    13: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/plugin_manager.rb:97:in `each'
    12: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/plugin_manager.rb:99:in `block in execute_plugins'
    11: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:23:in `post_build'
    10: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:23:in `each_key'
     9: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:30:in `block in post_build'
     8: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/file_wrapper.rb:52:in `open'
     7: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/file_wrapper.rb:52:in `open'
     6: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/lib/ceedling/file_wrapper.rb:53:in `block in open'
     5: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:33:in `block (2 levels) in post_build'
     4: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:57:in `reorganise_results'
     3: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:57:in `each'
     2: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:60:in `block in reorganise_results'
     1: from /usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:60:in `map'
/usr/lib/ruby/gems/2.7.0/gems/ceedling-0.31.1/plugins/junit_tests_report/lib/junit_tests_report.rb:60:in `block (2 levels) in reorganise_results': undefined method `merge' for nil:NilClass (NoMethodError)

I have been using:

• ceedling 0.31.1,
• ruby 2.7.7p221 (2022-11-24 revision 168ec2b1e5)

I run ceedling test:all gcov:all utils:gcov but in the end this error occurs.

This is the project.yml file

# Main ceedling project file

:project:
  :use_exceptions: FALSE
  :use_test_preprocessor: TRUE
  :use_auxiliary_dependencies: TRUE
  :build_root: .build/ceedling
  :test_file_prefix: test_
  :default_tasks:
    - test:all
  :options_paths:
    - ./test/unit_tests/options/

:environment:

:extension:
  :executable: .out

:paths:
  :test:
    - +:test/unit_tests/**
  :source:
    - src/**
    # - ./.build/
    # - /usr/include/glib-2.0/**
    # - /usr/lib/glib-2.0/include/**
    # - /usr/include/gio-unix-2.0/**
  :include: # Any header files not already in the source search path.
    - ./include/**
    - /usr/include/
    - /usr/include/glib-2.0/**
    - /usr/lib/glib-2.0/include/**
    - /usr/include/gio-unix-2.0/**
    - ./.build/
    - ./.build/introspection/**
    - ./subprojects/**

:cmock:
  :mock_prefix: mock_
  :when_no_prototypes: :warn
  :enforce_strict_ordering: TRUE
  :plugins:
    - :ignore_arg
    - :return_thru_ptr
    - :ignore
    - :callback
    - :expect_any_args
  :defines:
    - __G_LIB_H__
    - __G_IO_H__
    - __G_STDIO_H__
    - __GLIB_GOBJECT_H__
  :treat_as:
    uint8:    HEX8
    uint16:   HEX16
    uint32:   UINT32
    int8:     INT8
    bool:     UINT8
  :unity_helper:
    - ./test/unit_tests/ceedling_mock_helper.h


# LIBRARIES
# These libraries are automatically injected into the build process. Those specified as
# common will be used in all types of builds. Otherwise, libraries can be injected in just
# tests or releases. These options are MERGED with the options in supplemental yaml files.
:libraries:
  :placement: :end
  :flag: "-l${1}"  # or "-L ${1}" for example
  :common: &common_libraries []
  :test:
    - *common_libraries
    - glib-2.0
    - gio-2.0
  :release:
    - *common_libraries

:plugins:
  :load_paths:
  :enabled:
    - colour_report
    - gcov
    - stdout_pretty_tests_report
    - module_generator
    - raw_output_report
    - junit_tests_report

:junit_tests_report:
  :artifact_filename: report.junit.xml

:gcov:
  :utilities:
    - gcovr           # Use gcovr to create the specified reports (default).
  :gcovr:
    :html_medium_threshold: 75
    :html_high_threshold: 90
    :exclude_unreachable_branches: true
    :report_include: "^src/"
    :report_exclude: "^.build/"
  :reports:
    - HtmlDetailed
    - JSON