When I create a multiple configuration project with user-defined axes, the variables are not accessible to the rest of the project. For example, if I create the variable buildConfig, and give it two values, Release and Debug, I can show it using a batch command:

echo buildConfig = %buildConfig%

This correctly displays "buildConfig = Release" or "buildConfig = Debug".

But if I add a shell command:

echo buildConfig = $buildConfig

This shows only "buildConfig = "

Neither %buildConfig%, $buildConfig, nor ${buildConfig} results in the correct replacement.

I have only tested this on Windows