What does Zig Build do here?

[median dagger]

I was following this here https://zigtools.org/zls/guides/build-on-save/ and the zig build code included defining two different executable objects, one for the installed executable and one for a check executable. I thought that was a bit verbose, so I tried to create a version of the code which just uses the one executable, however it for some reason still installs the executable when running the check step. The code is as follows:

const std = @import("std");

pub fn build(b: *std.Build) void {
    const optimize = b.standardOptimizeOption(.{});
    const exe = b.addExecutable(.{
        .name = "PLACEHOLDER",
        .root_source_file = b.path("src/main.zig"),
        .optimize = optimize,
        .target = target,
    });

    const checkStep = b.step("check", "Check if the executable compiles");
    checkStep.dependOn(&exe.step);

    const installExe = b.addInstallArtifact(exe, .{});
    b.getInstallStep().dependOn(&installExe.step);

    const runExe = b.addRunArtifact(exe);
    const runStep = b.step("run", "Run the executable");
    runStep.dependOn(&runExe.step);
}

Can someone explain to me what exactly the build script is doing and if there's a way to do it without defining two executables?

[jade yew]

if there's a way to do it without defining two executables?
there is not. you can put it in a function though, if you want, and just call that twice

as for what exactly is happening: when you (or, addInstallArtifact in this case) request the output file from the build step, it registers at configure time that that file is required

so it always builds it, because there's a build step that requires it

even if that build step is never actually run

[tight geyser]

sure there is, use an option instead of a step and make anything related to installing the exe conditional

[jade yew]

okay, yeah fair

but zls looks for a check step, not a -Dno-bin option

[tight geyser]

well you can change the args it uses, check is just a default