FAQ

The bundled Zig toolchain is incomplete. zig needs its lib folder beside zig.exe, and when bin\res\zig\lib\std\std.zig is missing every build fails with this message, which is zig's own.

To fix it:

1. Delete the bin\res\zig folder.
2. Extract the release zip again with 7-Zip or WinRAR.
3. Check that bin\res\zig\lib\std\std.zig exists.

The first build for a target also compiles the libraries every program links (the C runtime, libc++, libc++abi, libunwind, compiler_rt and the system import libraries) and keeps them in zig's cache, bin\res\zig\.zig-cache. That build can take a few minutes.

Later builds for that target reuse them, at another optimize level too, and take seconds. The first build for the other target (x86_64-linux-gnu) compiles its own libraries once in the same way. Deleting bin\res\zig\.zig-cache makes the next build of each target slow again. How a build works is in Building.

A Linux build run on Windows (-t x86_64-linux-gnu -r) runs under WSL2, and its window is shown by WSLg, whose compositor (Weston) gives every Linux program a display scale of 1 by default. A program that sizes its window by that scale (the SDL3 examples call SDL_GetWindowDisplayScale) opens at 1x on a 150% monitor, smaller than the same program built for Windows.

To make WSLg follow each monitor's Windows scale, create the file .wslgconfig in your Windows user folder (C:\Users\<you>\.wslgconfig for WSL from the Microsoft Store; C:\ProgramData\Microsoft\WSL\.wslgconfig for the WSL built into Windows) holding:

[system-distro-env]
WESTON_RDP_HI_DPI_SCALING=true
WESTON_RDP_FRACTIONAL_HI_DPI_SCALING=true

then run wsl --shutdown (WSLg reads the file when it starts). The Linux window then opens at the size Windows scales it to on that monitor. The program itself still reads a scale of 1: Windows enlarges the window, the program does not draw at the higher resolution.

Leave out WESTON_RDP_DEBUG_DESKTOP_SCALING_FACTOR: it forces one factor on every monitor instead of each monitor's own.