zig build: `getty-zig/json` no longer compiles

[cr0sh]

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Zig Version

0.11.0-dev.3262+df909da5d

Steps to Reproduce and Observed Behavior

(Steps taken from https://github.com/getty-zig/getty#quick-start)

1. zig init-exe
2. Replace build.zig with

   const std = @import("std");
   
   pub fn build(b: *std.Build) void {
       const target = b.standardTargetOptions(.{});
       const optimize = b.standardOptimizeOption(.{});
   
       const opts = .{ .target = target, .optimize = optimize };
       const json_mod = b.dependency("json", opts).module("json");
   
       const exe = b.addExecutable(.{
           .name = "quick-start",
           .root_source_file = .{ .path = "src/main.zig" },
           .target = target,
           .optimize = optimize,
       });
   
       exe.addModule("json", json_mod);
   
       const run_cmd = b.addRunArtifact(exe);
       const run_step = b.step("run", "Run the app");
       run_step.dependOn(&run_cmd.step);
   }
   

3. Create build.zig.zon with

   .{
       .name = "quick-start",
       .version = "0.0.0",
       .dependencies = .{
           .json = .{
               .url = "https://github.com/getty-zig/json/archive/5a64449.tar.gz",
               .hash = "122087fe6d2b141548103e98e4324ac0ab889e7d50d82e186f396d90f55a942aef61",
           },
       },
   }
   

4. thread 245443 panic: A top-level step with name "clean" already exists
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/debug.zig:317:22: 0x10290ebdf in panicExtra__anon_44215 (build)
       std.builtin.panic(msg, trace, ret_addr);
                        ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/debug.zig:292:15: 0x1028dfb9b in panic__anon_27790 (build)
       panicExtra(null, null, format, args);
                 ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:971:44: 0x1028b195f in step (build)
       if (gop.found_existing) std.debug.panic("A top-level step with name \"{s}\" already exists", .{name});
                                              ^
   /Users/namjh/.cache/zig/p/1220c649e62d6bb0e07ac6b02711f76254f1dd1875859ad075873d248fb820f68d66/build.zig:116:30: 0x1029636b7 in clean (build)
       const clean_step = b.step("clean", "Remove project artifacts");
                                ^
   /Users/namjh/.cache/zig/p/1220c649e62d6bb0e07ac6b02711f76254f1dd1875859ad075873d248fb820f68d66/build.zig:17:10: 0x102922617 in build (build)
       clean(b);
            ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1602:33: 0x1028fb907 in runBuild__anon_44111 (build)
           .Void => build_zig.build(b),
                                   ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1586:25: 0x1028da89b in dependencyInner__anon_27494 (build)
       sub_builder.runBuild(build_zig) catch @panic("unhandled error");
                           ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1536:35: 0x1028b0e27 in dependency__anon_11051 (build)
               return dependencyInner(b, name, build_root, build_zig, args);
                                     ^
   /Users/namjh/.cache/zig/p/122087fe6d2b141548103e98e4324ac0ab889e7d50d82e186f396d90f55a942aef61/build.zig:13:38: 0x102922ecb in build (build)
       const getty_module = b.dependency("getty", dep_opts).module("getty");
                                        ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1602:33: 0x1028fbd6b in runBuild__anon_44116 (build)
           .Void => build_zig.build(b),
                                   ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1586:25: 0x1028daf73 in dependencyInner__anon_27509 (build)
       sub_builder.runBuild(build_zig) catch @panic("unhandled error");
                           ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1536:35: 0x1028b10ff in dependency__anon_11051 (build)
               return dependencyInner(b, name, build_root, build_zig, args);
                                     ^
   /Users/namjh/dev/hello-getty/build.zig:8:34: 0x102869847 in build (build)
       const json_mod = b.dependency("json", opts).module("json");
                                    ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/Build.zig:1602:33: 0x102855f87 in runBuild__anon_6636 (build)
           .Void => build_zig.build(b),
                                   ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/build_runner.zig:292:29: 0x102851007 in main (build)
           try builder.runBuild(root);
                               ^
   /opt/homebrew/Cellar/zig/HEAD-df909da/lib/zig/std/start.zig:609:37: 0x10285649b in main (build)
               const result = root.main() catch |err| {
                                       ^
   ???:?:?: 0x181eebf27 in ??? (???)
   ???:?:?: 0xb017ffffffffffff in ??? (???)
   error: the following build command crashed:
   /Users/namjh/dev/hello-getty/zig-cache/o/32c71ae3eaaf465b6d86e35423d4e27c/build /opt/homebrew/Cellar/zig/HEAD-df909da/bin/zig /Users/namjh/dev/hello-getty /Users/namjh/dev/hello-getty/zig-cache /Users/namjh/.cache/zig run
   

For some context, getty-zig/json depends on getty-zig/getty, and both package defines a step named "clean", which would be a trouble.

Expected Behavior

Compiliation succeeds on 0.11.0-dev.2563+35f9c8444, so it could be affected by a breaking change.

[Deecellar]

Would call it, mismatching steps on build.zig or something?

zig mantainers shouldn't wor about package breakage, but the error itself is weird

[nektro]

• copied the quick start from https://github.com/getty-zig/getty/blob/7d1332427af55247a8520e5f77cf82aeb57a480a/README.md
• got https://gist.github.com/nektro/9744a80b546341e352b56aae8957941c
• ran zig build run with 0.11.0-dev.2986+012f9a97e
• got the same error as https://github.com/ziglang/zig/issues/15590

[matu3ba]

Likely introduced by https://github.com/ziglang/zig/pull/14872 as unintended side effect (I did not bisect this).

[nektro]

re-tried with 0.11.0-dev.3000+d71a43ec2 and got the same error as well. was not able to repro title issue

[cr0sh]

@nektro What platform are you testing on? I'm on MacOS aarch64 13.3.1a(Ventura), and zig build run downloads the module without any issue. I removed ~/.cache and zig-cache to ensure the modules are freshly downloaded, but correct me if I'm wrong.

[nektro]

I'm on Linux x86_64, NixOS 22.11 in particular

[cr0sh]

Hmm that differs. I think we should wait for https://github.com/ziglang/zig/issues/15590 to be resolved first?

[cr0sh]

Still fails on 0.11.0-dev.3262+df909da5d. Updated the instructions. (FYI the getty maintainer temporarily removed the 'clean' step on the latest master, so you may not reproduce the issue correctly if used)

[andrewrk]

Note that it should be perfectly fine for any packages to have same-named top level steps, since they each have an independent top level step namespace. There is something a bit more subtle and tricky going on here.

As a first step, we can collect a stack trace where a top level step is defined, and then print it when such a conflict occurs. That will make for a nicer debugging experience, no matter what the root cause of this ends up being.