Hi, thanks for sharing this problem.
I can reproduce this in v3.9 also. It looks like the mechanism for introducing this constant is somehow failing under a CPS build system.
I've noted this down to be fixed.
To work around this, I suggest changing your project file to introduce a build condition around a manually declared build constant, for example:
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
<DefineConstants Condition="'$(NCrunch)' == '1'">TRACE;DEBUG;NETCOREAPP1_1;NCRUNCH</DefineConstants>
</PropertyGroup>