I currently work on a project that uses NixOS tests for testing of an orchestration-ish tool. We primarily build on top of Incus and have a relatively expensive bootstrapping process (5 minutes wall time) to get Incus container images into the Incus store.
This makes it prohibitive to have multiple independent NixOS tests because each test replicates this setup cost. I would like, if possible, to re-use the test VM state after the bootstrapping process for multiple independent tests. I couldn’t find any documentation on this (or NixOS tests caching in general). So effectively bootstrap the VM once and re-use this base state for each test.
Does someone know how what would have to be done to re-use a VM state based on a NixOS test for partial caching?