Introduction:

When validating or processing a config.yml using the CircleCI CLI, some users may experience the following error

Error: config compilation request returned an error: invalid character 'I' looking for beginning of value

These errors are usually a result of upgrading to a newer release and a new token results in this behavior being mitigated.

Prerequisites:

• CircleCI CLI Installed on your machine 
• Personal API Token
  • These are generated on this page in your user settings: https://app.circleci.com/settings/user/tokens

Solutions:

• Pass your existing API token into the command using the --token flag

  • This can be done using an existing token or by generating a new Personal API Token

  • circleci --token <personal-api-token> config process .circleci/continue_config.yml -v

• Rotate your Token

  • Navigate to your User Settings Page and generate a new API token for use with the CircleCI CLI

• Use circleci setup with your newly generated token

  • Follow the prompts that result and keep the generated new API token handy to set up the CLI with it
  • https://circleci-public.github.io/circleci-cli/circleci_setup.html 

Outcome:

After rotating or passing the token into the command, the circleci commands run will behave as expected.

Additional Notes:

• We have observed that this occurs mostly for users on macOS who have installed using brew but can impact any CircleCI CLI users after upgrading

Additional Resources:

• • CircleCI CLI Manual
  • CircleCI CLI - Running circleci local execute Results in "not implemented for cgroup v2 unified hierarchy" Error