Asar does not build on MinGW64 because CMake wrongly selects Linux file helpers

[repzilon]

I am trying to build Asar (asar_19 branch) on Windows with MinGW64. However, it does not work. CMake generates a Makefile containing instructions to compile the Linux file helpers instead of the Windows ones (or even the generic ones). Predictably, it fails to compile, GCC yelling about the missing constant to match a symbolic link as a file type (Windows support for symbolic links is sketchy at best).

I tried to fix this by editing src/asar/CMakeLists.txt, but it did not work. Can you look into this, please?

[repzilon]

Followups : @trillllian suggested me on Discord:

we have a toolchain file for mingw, use it like -DCMAKE_TOOLCHAIN_FILE=../cmake/mingw-x64.cmake

Yes, I am building on Windows [no cross-compiling]. However, calling cmake -DCMAKE_TOOLCHAIN_FILE=../cmake/mingw-x64.cmake src then make fails with

[...]/asar-1.91/src/asar/platform/file-helpers.h:3:10: fatal error: libstr.h: No such file or directory
    3 | #include "libstr.h"
      |          ^~~~~~~~~~

A -I<directory> option seems missing.

I later found out a working invocation: cmake -DMINGW=ON -DWIN32=ON src. This is a workaround however, because I should not need to pass arguments to cmake for configuring the build platform. Not passing such arguments is supposed to be the point of using cmake in the first place.