Windows build instructions are no longer valid

[zorbathut]

Bug description
The build instructions listed at https://github.com/google/agi/blob/master/BUILDING.md are no longer valid.

• choco install bazel --version 5.2.0 exits with an error; it appears 5.2.0 is no longer available. It will install without the version flag, however. (Sorry, I don't have the error available anymore!)
• http://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-gcc-10.2.0-10-any.pkg.tar.zst and http://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-gcc-libs-10.2.0-10-any.pkg.tar.zst now generate 404 errors and therefore cannot be installed. I solved this with pacman -S gcc gcc-libs.

After making these changes, I was able to start the build until it aborted with an error:

/external/local_config_cc/file_collector.cpp:19:10: fatal error: direct.h: No such file or directory
   19 | #include <direct.h>
      |          ^~~~~~~~~~
compilation terminated.

at which point I kinda gave up, since I don't know which of my workarounds may have caused the issue.

If you'd like more information, please let me know!

A build Dockerfile would be very appreciated.

[ttanatb]

It's could be from the pacman -S gcc gcc-libs

I ended up using gcc 10.3

curl -O https://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-gcc-10.3.0-8-any.pkg.tar.zst
curl -O https://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-gcc-libs-10.3.0-8-any.pkg.tar.zst
curl -O https://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-binutils-2.37-4-any.pkg.tar.zst
pacman -U --noconfirm mingw-w64-x86_64-gcc-10.3.0-8-any.pkg.tar.zst mingw-w64-x86_64-gcc-libs-10.3.0-8-any.pkg.tar.zst mingw-w64-x86_64-binutils-2.37-4-any.pkg.tar.zst

[ttanatb]

An improved build process on windows (i.e. doesn't break when the hosted gcc lib goes down) makes sense, but we don't have the resources to invest in these improvements