Creating a minimal CMake template for C(++), running into issues as I learn CMake

I work with a few electrical engineers and am looking for ways to make it easier for them to write tests for the code they write, so I’m trying to create a template that covers a few basics with minimal setup on Windows. In the past I’ve mostly strung things together with make files, but that’s getting harder to maintain and doesn’t work well for IDE support.

There’s at least two well done templates to draw from:

github: TheLartians/ModernCppStarter

But I’m having trouble understanding what’s not working in my template.
For example in the ModernCPPStarter running ctest in the build directory finds the test executable just fine, but mine failes to find tests.exe in the Debug directory:

Process not started
[no such file or directory]
1/1 Test #1: My name is Bob ...................***Not Run   0.00 sec

My goal is to have something that works well on windows and linux at a minimum. I’d like to have it work well with vscode, clion, and sublime. I’d like to support clang and gcc. I’d also like to support embedded targets with at least gcc (arm-none-eabi-gcc) or clang

I currently have projects that string together some of those os and compiler combos with make files, but using make files doesn’t give me good IDE support.