I'm migrating our build system over to TeamCity and, because we have quite long build times, I'm trying to make good use of parallelism in build configurations. If two configs can run in parallel they are obviously not dependent on each other. However there are some cases where, if two parallel builds are serialised (due to lack of available agents) then I would prefer one to run ahead of another (for example one is a set of regression tests that I'd like to see the result of before a packaging step is run - but if resources are available I'd like them both to run concurrently).
I can't find an explicit way to specify ordering of logically independent builds. However I've observed that the build order tends to be lexicographical - although I'm not sure if that's on the config name or ID.
I could experiment but would prefer a more definite answer, if possible.
This used to be available as a plugin, but has since been bundled into the product.
Go to the build queue and click on Configure Build Priorities
If you add a class with a high number, you can then associate that with the build you'd like to be built first
Managing Build Priorities - TeamCity documentation
Hope this helps