crash when building docs

% zig build docs
zig build-obj docs Debug native: error: thread 15277 panic: reached unreachable code
/home/tw/code/zig/src/Autodoc.zig:478:13: 0x91fccff in resolveDeclName (zig)
            unreachable;
            ^
/home/tw/code/zig/src/Autodoc.zig:2679:61: 0x8eef0d7 in walkInstruction (zig)
            const decl_status = parent_scope.resolveDeclName(str_tok.start, file, inst.toOptional());
                                                            ^
/home/tw/code/zig/src/Autodoc.zig:5678:36: 0x91eb449 in walkRef (zig)
        return self.walkInstruction(
                                   ^
/home/tw/code/zig/src/Autodoc.zig:1577:61: 0x8eeaeb0 in walkInstruction (zig)
            const lhs: DocData.WalkResult = try self.walkRef(
                                                            ^
/home/tw/code/zig/src/Autodoc.zig:4211:49: 0x9523016 in analyzeDecl (zig)
    const walk_result = try self.walkInstruction(
                                                ^
/home/tw/code/zig/src/Autodoc.zig:4092:29: 0x91fb729 in analyzeAllDecls (zig)
        try self.analyzeDecl(
                            ^
/home/tw/code/zig/src/Autodoc.zig:3800:59: 0x8ee7bcf in walkInstruction (zig)
                    extra_index = try self.analyzeAllDecls(
                                                          ^
/home/tw/code/zig/src/Autodoc.zig:1083:40: 0x8ec9d1e in walkInstruction (zig)
            return self.walkInstruction(
                                       ^
/home/tw/code/zig/src/Autodoc.zig:5678:36: 0x91eb449 in walkRef (zig)
        return self.walkInstruction(
                                   ^
/home/tw/code/zig/src/Autodoc.zig:2799:32: 0x8edc75b in walkInstruction (zig)
            return self.walkRef(
                               ^
/home/tw/code/zig/src/Autodoc.zig:4211:49: 0x9523016 in analyzeDecl (zig)
    const walk_result = try self.walkInstruction(
                                                ^
/home/tw/code/zig/src/Autodoc.zig:4092:29: 0x91fb729 in analyzeAllDecls (zig)
        try self.analyzeDecl(
                            ^
/home/tw/code/zig/src/Autodoc.zig:3800:59: 0x8ee7bcf in walkInstruction (zig)
                    extra_index = try self.analyzeAllDecls(
                                                          ^
/home/tw/code/zig/src/Autodoc.zig:1083:40: 0x8ec9d1e in walkInstruction (zig)
            return self.walkInstruction(
                                       ^
/home/tw/code/zig/src/Autodoc.zig:5678:36: 0x91eb449 in walkRef (zig)
        return self.walkInstruction(
                                   ^
/home/tw/code/zig/src/Autodoc.zig:2799:32: 0x8edc75b in walkInstruction (zig)
            return self.walkRef(
                               ^
/home/tw/code/zig/src/Autodoc.zig:4211:49: 0x9523016 in analyzeDecl (zig)
    const walk_result = try self.walkInstruction(
                                                ^
/home/tw/code/zig/src/Autodoc.zig:4092:29: 0x91fb729 in analyzeAllDecls (zig)
        try self.analyzeDecl(
                            ^
/home/tw/code/zig/src/Autodoc.zig:3800:59: 0x8ee7bcf in walkInstruction (zig)
                    extra_index = try self.analyzeAllDecls(
                                                          ^
/home/tw/code/zig/src/Autodoc.zig:1051:44: 0x8ec9531 in walkInstruction (zig)
                return self.walkInstruction(
                                           ^
/home/tw/code/zig/src/Autodoc.zig:5678:36: 0x91eb449 in walkRef (zig)
        return self.walkInstruction(
                                   ^
/home/tw/code/zig/src/Autodoc.zig:2799:32: 0x8edc75b in walkInstruction (zig)
            return self.walkRef(
                               ^
/home/tw/code/zig/src/Autodoc.zig:4211:49: 0x9523016 in analyzeDecl (zig)
    const walk_result = try self.walkInstruction(
                                                ^
/home/tw/code/zig/src/Autodoc.zig:4092:29: 0x91fb729 in analyzeAllDecls (zig)
        try self.analyzeDecl(
                            ^
/home/tw/code/zig/src/Autodoc.zig:3800:59: 0x8ee7bcf in walkInstruction (zig)
                    extra_index = try self.analyzeAllDecls(
                                                          ^
/home/tw/code/zig/src/Autodoc.zig:332:33: 0x8ec2bab in generateZirData (zig)
    _ = try self.walkInstruction(
                                ^
/home/tw/code/zig/src/Autodoc.zig:91:32: 0x8ef2e9e in generate (zig)
    try autodoc.generateZirData(output_dir);
                               ^
/home/tw/code/zig/src/Compilation.zig:2642:33: 0x8ef336c in maybeGenerateAutodocs (zig)
            try Autodoc.generate(mod, dir);
                                ^
/home/tw/code/zig/src/Compilation.zig:2592:38: 0x8ef5e5c in update (zig)
            try maybeGenerateAutodocs(comp, main_progress_node);
                                     ^
/home/tw/code/zig/src/main.zig:3843:36: 0x8f22e41 in serve (zig)
                    try comp.update(main_progress_node);
                                   ^
/home/tw/code/zig/src/main.zig:3637:22: 0x8f4690a in buildOutputType (zig)
            try serve(
                     ^
/home/tw/code/zig/src/main.zig:283:31: 0x8d57bef in mainArgs (zig)
        return buildOutputType(gpa, arena, args, .{ .build = .Obj });
                              ^
/home/tw/code/zig/src/main.zig:223:20: 0x8d54d25 in main (zig)
    return mainArgs(gpa, arena, args);
                   ^
/home/tw/code/zig/lib/std/start.zig:585:37: 0x8d5473e in main (zig)
            const result = root.main() catch |err| {
                                    ^
../sysdeps/nptl/libc_start_call_main.h:58:16: 0x7f1b34a4520b in __libc_start_call_main (../sysdeps/x86/libc-start.c)
../csu/libc-start.c:381:3: 0x7f1b34a452bb in __libc_start_main_impl (../sysdeps/x86/libc-start.c)
../sysdeps/x86_64/start.S:115:0: 0x4107220 in ??? (../sysdeps/x86_64/start.S)
???:?:?: 0x0 in ??? (???)

zig build-obj docs Debug native: error: the following command terminated unexpectedly:
/home/tw/code/zig/stage3/bin/zig build-obj /home/tw/code/zbpf/src/docs/docs.zig -fno-emit-bin -femit-docs --cache-dir /home/tw/code/zbpf/zig-cache --global-cache-dir /tmp/.cache/zig --name docs --mod vmlinux::/home/tw/code/zbpf/src/docs/vmlinux.zig --mod bpf:vmlinux:/home/tw/code/zbpf/src/bpf/root.zig --deps bpf --listen=- 
Build Summary: 0/3 steps succeeded; 1 failed (disable with --summary none)
docs transitive failure
+- install generated/ transitive failure
   +- zig build-obj docs Debug native failure
error: the following build command failed with exit code 1:
/home/tw/code/zbpf/zig-cache/o/c7f5bb55fb2fea83ef24c274877c67c0/build /home/tw/code/zig/stage3/bin/zig /home/tw/code/zbpf /home/tw/code/zbpf/zig-cache /tmp/.cache/zig --seed 0xc722c30f docs
tw4452852 / zbpf

crash when building docs #7
