https://github.com/ziglang/zig/issues/17818

build.zig

const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

    const exe = b.addExecutable(.{
        .name = "test",
        .root_source_file = .{ .path = "main.zig" },
        .target = target,
        .optimize = optimize,
    });

    const langs_dep = b.dependency("languages", .{});
    exe.addModule("iso-639-languages", langs_dep.module("iso-639-languages"));

    b.installArtifact(exe);

    const run_cmd = b.addRunArtifact(exe);

    run_cmd.step.dependOn(b.getInstallStep());

    if (b.args) |args| {
        run_cmd.addArgs(args);
    }

    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);
}

build.zig.zon

.{
    .name = "zig17818",
    .version = "0.0.1",

    .dependencies = .{
        .languages = .{
            .url = "https://github.com/nektro/zig-iso-639-languages/archive/f0cd4a8f19d8791335b7a0940212e4073fa645a6.tar.gz",
            .hash = "122066b0071358166df838aa57ccdfcd239949e2a2bed0fa701f8b744c054c34253d",
            .build_file = "build.zig.zig",
        },
    },
    .paths = .{
        ".",
    },
}

main.zig

const std = @import("std");
const langs = @import("iso-639-languages");

pub fn main() !void {
    std.log.info("{d}", .{std.meta.fields(langs.Alpha2Code).len});
    std.log.info("{d}", .{std.meta.fields(langs.Alpha3Code).len});
}