LoadError: cannot load such file -- rspec_junit_formatter

エラー全体（CircleCIで表示）

!/bin/bash -eo pipefail
mkdir /tmp/test-results
TEST_FILES="$(circleci tests glob "spec/**/*_spec.rb" |
circleci tests split --split-by=timings)"
bundle exec rspec
--format progress
--format RspecJunitFormatter
--out /tmp/test-results/rspec.xml
--format progress
$TEST_FILES
Error reading historical timing data: file does not exist
Requested weighting by historical based timing, but they are not present. Falling back to weighting by name.
No examples found.
bundler: failed to load command: rspec (/home/circleci/portfolio_AWS/vendor/bundle/ruby/2.5.0/bin/rspec)
LoadError: cannot load such file -- rspec_junit_formatter

原因箇所

cannot load such file -- rspec_junit_formatter

解決方法

Gemfileに次を追記。

group :test do
  gem 'rspec_junit_formatter'
end

参考記事