AltCover.Cake not running on Windows when assemblies were built in a (different) Windows GitHub runner

[HebaruSan]

Hi @SteveGilham,

We have a GitHub Actions/Workflow pipeline where one container builds the assemblies and another container tests them. This works well today with Linux containers using Mono and msbuild (but only for net481), using the altcover.exe commands directly to instrument and collect coverage data separately before and after the testing step.

My goal in KSP-CKAN/CKAN#4449 is to capture coverage data for both Linux and Windows. We have multiple target frameworks with one test assembly per target framework, so we use dotnet test on Windows, and I am trying to use AltCover.Cake for instrumentation and collection. It works flawlessly when I run it locally with locally-built assemblies, or if a single container does both the build and test steps. But when I copy the assemblies from one container to another, or download the built assemblies to my local Windows machine, my AltCover.Cake logic seems to have no effect. No instrumented files are generated, no coverage summary is printed, and no coverage files are generated. Not even an error message.

I find this surprising because all of the needed tools are installed, the assemblies are in the expected locations, etc. I have been trying to puzzle it out for a couple of days now, and I haven't really made progress. Is there anything that comes to mind that might help me to figure out what is different or missing about the remotely built assemblies?

(I have figured out that the LocalSource option can't be used when the absolute path of the source files are different, so that's already disabled.)

Thanks in advance for any help!