configure:
pd 0.51.3 is now configured
Platform: Unknown
Clearly, configure failed and it never set the platform. The platform-specific / host checks failed and it probably half-defaults to building for Linux which is why it's trying to build the OSS audio backend.
Now, looking at the beginning of the same configure log, we see:
checking build system type... x86_64-pc-msys
checking host system type... x86_64-pc-msys
configure: iPhone SDK only available for arm-apple-darwin hosts, skipping tests
configure: Android SDK only available for arm-linux hosts, skipping tests
Hmm. The canonical host it's seeing is "x86_64-pc-msys" which is not one we actually support directly. What we support for building on windows with autootols is "mingw" see
So I think this a configuration issue with your setup as you are somehow not building with mingw as we have listed in the INSTALL.txt. One reason for this may be using the wrong shell, ie. MSYS2 instead of the explicit MinGW64 shell. It's been a few years since I've worked directly with MinGW & Pd, so the naming may have changed... which is also why we wrote the steps in INSTALL.txt. :)