I'm running simplecov / codeclimate. Bumping from v0.17.1 to v0.18.0 of SimpleCov causes the reporter to fail:

#!/bin/bash -eo pipefail
curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-$CC_TEST_REPORTER_VERSION > ./cc-test-reporter
chmod +x ./cc-test-reporter
./cc-test-reporter format-coverage -t simplecov coverage/.resultset.json
./cc-test-reporter upload-coverage
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

100   178  100   178    0     0  14833      0 --:--:-- --:--:-- --:--:-- 14833

100 12.1M  100 12.1M    0     0  82.8M      0 --:--:-- --:--:-- --:--:-- 82.8M
Error: json: cannot unmarshal object into Go struct field input.coverage of type []formatters.NullInt
Usage:
  cc-test-reporter format-coverage [coverage file] [flags]

Flags:
      --add-prefix string   add this prefix to file paths
  -t, --input-type string   type of input source to use [clover, cobertura, coverage.py, excoveralls, gcov, gocov, jacoco, lcov, simplecov, xccov]
  -o, --output string       output path (default "coverage/codeclimate.json")
  -p, --prefix string       the root directory where the coverage analysis was performed (default "/home/circleci/project")

Global Flags:
  -d, --debug   run in debug mode


Exited with code exit status 255

Possibly related to the formatting?

Old: https://15129-99061924-gh.circle-artifacts.com/0/coverage/.resultset.json
New: https://15169-99061924-gh.circle-artifacts.com/0/coverage/.resultset.json

PR / CI for reference: ksylvest/playground#892 / https://circleci.com/gh/ksylvest/playground/15169#artifacts/containers/0