Sentry alert: System exit in pipeline config

[lucyb]

Sentry alert: https://ebm-datalab.sentry.io/issues/5232951409/?alert_rule_id=10884789&alert_type=issue&notification_uuid=edfee2e8-c6b3-476f-88e3-ae9b44c13958&project=5443358&referrer=slack

Browsing to this URL caused a System Exit to occur. It would be good to understand why this error was thrown.

[iaindillingham]

I'm going to move this from Next to Later. It's been on the board for a couple of weeks and we haven't had time to investigate. The errors are infrequent, but non-critical.