Summary
When Aspire passes --container-runtime podman to dcp start-apiserver, DCP's API server starts successfully but then forwards the --container-runtime flag to the dcp run-controllers subprocess. The run-controllers subcommand does not accept this flag and crashes immediately with exit code 1. Because the controllers never start, DCP Service objects are never reconciled, and Aspire times out waiting for effective addresses.
The Full Writeup
See the full writeup from an issue on the dotnet/aspire repo prior to landing here in a microsoft/dcp github repo.
dotnet/aspire#12241 (comment)