During installation, under "Workloads" (or "Individual components"), select "C++ build tools" and ensure the latest versions of "MSVCv142 - VS 2019 C++ x64/x86 build tools" and "Windows 10 SDK" are selected. (as per @mrhelixx)
This should be mentioned either in the README before the instructions to run pip install -r requirements.txt (so before line 78), or in the FAQ.
On Windows, it's necessary to install Microsoft C++ Build Tools:
This should be mentioned either in the README before the instructions to run
pip install -r requirements.txt
(so before line 78), or in the FAQ.Happy to open a PR.
There are a number of issues related to this: https://github.com/RVC-Project/Retrieval-based-Voice-Conversion-WebUI/issues?q=is%3Aissue+Microsoft+C%2B%2B+Build+Tools (not all of these of course, but quite a few)
193
499
523
1103
1608
1857