Zig build required option for a particular step

squeek502 · October 23, 2024, 12:55pm

There’s actually an example of exactly what you’re looking for in Zig’s build.zig:

ziglang/zig/blob/2d888a8e639856e8cb6e4c6f9e6a27647b464952/build.zig#L561-L576


      
          const update_mingw_step = b.step("update-mingw", "Update zig's bundled mingw");
          const opt_mingw_src_path = b.option([]const u8, "mingw-src", "path to mingw-w64 source directory");
          if (opt_mingw_src_path) |mingw_src_path| {
              const update_mingw_exe = b.addExecutable(.{
                  .name = "update_mingw",
                  .target = b.graph.host,
                  .root_source_file = b.path("tools/update_mingw.zig"),
              });
              const update_mingw_run = b.addRunArtifact(update_mingw_exe);
              update_mingw_run.addDirectoryArg(b.path("lib"));
              update_mingw_run.addDirectoryArg(.{ .cwd_relative = mingw_src_path });
          
              update_mingw_step.dependOn(&update_mingw_run.step);
          } else {
              update_mingw_step.dependOn(&b.addFail("The -Dmingw-src=... option is required for this step").step);
          }

(and another here)