If you mistakenly have a variable reference itself it gets stuck in what appears to be an infinite loop. I've waited many minutes, and the deploy process provides no feedback nor does it error out.

An example I mistakenly did due to a bad cut and paste in my serverless.yml:

provider:
  environment:
    SOME_VARIABLE: ${self:provider.environment.SOME_VARIABLE}

sls deploy -v hangs with no output

Other mention: #4687 (comment)

service: test
provider:
  name: aws
  runtime: nodejs12.x
  environment:
    SOME_VARIABLE: ${self:provider.environment.SOME_VARIABLE}
functions:
  hello:
    handler: handler.hello

sls deploy -v

Installed version

Framework Core: 1.72.0
Plugin: 3.6.13
SDK: 2.3.1
Components: 2.30.12