Version:

$ openshift-install version
4.9.25

Platform:
AWS IPI

What happened?
When provisioning a cluster using pre-provisioned VPC/subnets, if the dhcp-options-set is misconfigured for the subnet, installation will fail with no detailed error beyond bootstrap failed.

For example, if you use the following dhcp-options-set that lacks DNS server configuration, installation will not complete:
aws ec2 create-dhcp-options --dhcp-configurations '[

]'

What did you expect to happen?
The installer to do either pre-flight verification that basic settings like DNS don't work, or the installer to provide guidance as to what part of the installation failed in order to allow the user to diagnose and correct it.

How to reproduce it (as minimally and precisely as possible)?

Create a VPC/subnets with default settings, but create a faulty DHCP options set above.
Pass the subnets into the openshift-installer, and proceed with an IPI install with default settings.