Build.addOptions: use of undeclared identifier 'build'

[evaleek]

I’m trying to declare an enum type in my build.zig, create a build flag for it with Build.option(), and pass the flag down to the module with Build.addOptions() → Module.addOptions().

        const UnixWindowingSystem = enum { x11, wayland };
        const linux_window_hint = b.option(
            UnixWindowingSystem,
            "linux_windowing",
            "If targeting Linux, hint the windowing system.",
        );
        const options = b.addOptions();
        options.addOption(
            ?UnixWindowingSystem,
            "linux_windowing",
            linux_window_hint,
        );

        module.addOptions("options", options);

When I compile:

.zig-cache/c/2e7c8fa2ad0f40ba4fb243e0c52d0261/options.zig:1:29: error: use of undeclared identifier 'build'
pub const linux_windowing: ?build.build.UnixWindowingSystem = null;
                            ^~~~~

I see the issue is that the generated options.zig expects a missing build module where the type should have been passed down.

How do I give it the type? I’ve already tried putting the identifier at every scope of build.zig and searched through the std docs… sorry if I missed the right function. Is this not something I’m able to do?

[castholm]

std.Build.Step.Options generating invalid code for arrays/slices/optionals of custom types is a known issue:

Build options: passing structs fails

Arrays of Types in Build Step Options Results in Badly Generated Code

There are two open pull requests (1, 2) that attempt to fix this but they are not passing CI or have been abandoned.

As a workaround you could define the enum as enum { none, x11, wayland }, define the option as non-optional and use .none in place of null.