Error compiling piper.cpp for Windows (MSVC)

[pvrose]

I am getting a compile error when trying to build libpiper in Developer PowerShell in MSVC 2026.

See attachment:
temp.txt

Thanks Phil.

[pvrose]

I can see what is happening. Onnxruntime is expecting the model path to be const wchar_t* in Windows rather than const char*. This is set in a #DEFINE in onnxruntine_c_api.h. The only thing I can see to do without changing the piper API is to convert the string before the call to Ort::Session.

[w5xd]

I ran into the same problem. Fixing the wchar_t problem is not enough. I submitted a pull request that allows build in Visual Studio 2026:
#143

[pvrose]

Thanks Wayne.

Taking your fork has allowed me to progress. I managed to get libpiper to compile OK with a minor tweak to the CMakeLists.txt file as the espeak-ng UCD library was created in a different location than expected. This is probably an environmental issue at my end.

Phil.