Error Unable to setup base domain mappings for serverless custom domain

In serverless.yml, under custom, I have the following code (with dummy values here):

customDomain:
    domainName: myhost.mydomain.com
    basePath: ''
    stage: ${self:provider:stage}
    createRouteS3Record: true
    endpointType: 'edge'
    securityPolicy: tls_1_2
    certificateArn: 'arn:aws:acm:.................'
    hostZoneId: 'P4OCK4S1PSTZK' 

when I execute serverless deploy, everything goes smooth. the Api get generated properly for my function. (Under functions i have events: http)

However after the API getting generated lambda getting deployed, I get the following error:

Error: Error: Unable to setup base domain mappings for myhost.mydomain.com

i do not get much info other than https://forum.serverless.com/t/error-unable-to-setup-base-domain-mappings/11395 Do not know how to include api versions in serverless if that is the solution.

Well small things can cause big problems and are very hard to figure out at times. I found that stage: ${self:provider:stage} was wrong, it should have been stage: ${self:provider.stage}. The colon after provider was the culprit.