Unexpected token '╭', "╭─ info ──"... is not valid JSON

[octipus]

Theme check action started to fail as of this morning which appears to be caused by index.js file.
However, i cannot find the ╭─ info ── mentioned in the error, anywhere in the index.js file.
This workflow has not been changed in the past 8 months.

[octipus]

So it appears that the theme-check-action, by default, runs using the lates Shopify CLI which was causing this issue.
We have fixed this by specifying an previous version of the CLI in the action flag

[charlienaud]

Same here, I had to downgrade to an older version

It is related to the new notification system introduced in the latest @shopify/cli version.
More details here

[aswamy]

I believe this is already fixed on the main CLI branch. The next CLI release should fix this.

Shopify/cli#4910