It is stuck at the point where the image is supposed to have been pushed:
The push refers to repository [123456789123.dkr.ecr.us-east-1.amazonaws.com/cdk-hnb659fds-container-assets-123456789123-us-east-1]
5f70bf18a086: Preparing
...
ffb3cc8166fd: Pushed
41cc91312edea76dd64e98cc1c80d6c3751c805cbf8e6c8d7eda37f751ac2474: digest: sha256:bac65befc114dca10dc6ba6ab422ccbcb45d5ad090f77527f098cd4cf13fa70f size: 3242
In my case, it was not actually stuck. Earlier it asked my confirmation and started to print the Docker build logs so I missed the question:
Do you wish to deploy these changes (y/n)? #0 building with "desktop-linux" instance using docker driver
#1 [internal] load .dockerignore
#1 transferring context: 2B done
#1 DONE 0.0s
So I just had to press "Enter" and it printed the question again.