I recently came across a “cannot access install” error when deploying from a BitBucket repo Pipeline to WP Engine.

The error occurred on the rsync command, but during debugging I got the same problem with a simple SSH connect.  Nothing had changed on either setup recently.

I contacted WP Support and we worked through debugging the problem.  We couldn’t find the cause, and so I deleted the SSH key pair from BitBucket, and created a new pair.

I then added the new public key to WP Engine, and everything worked again.

I’m putting this out here in case this helps someone else.