Commit d09c1aef02788bcea0a3e3b0f7507c4f3e823295 | zig

author	Andrew Kelley <andrew@ziglang.org> 2026-09-25 11:47:25-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2026-09-25 11:47:25-07:00
log	d09c1aef02788bcea0a3e3b0f7507c4f3e823295
tree	d2b6e2868baddb5f0e7fe79b326d31a900d09c1c
parent	7cef4755c33ca77137fb7e4d83146e27b5703685

maker: serialize compilation errors of configurer over the build protocol

serves an ErrorBundle as a configuration_failed message instead of
configuration message upon connection. at this point the protocol enters
an invalid state and the process will need to be restarted in order to
reconfigure. in the future, build server should outlive
reconfigurations.

closes #36389

4 files changed, 54 insertions(+), 68 deletions(-)

lib
- compiler
  - Maker.zig
- std
  - zig.zig
  - zig
    Server.zig
tools
- bsp.zig

lib/compiler/Maker.zig+8-2

lib/std/zig.zig+17-7

 @@ -1713,6 +1713,9 @@ pub const BuildExeSubprocessOptions = struct {
     cpu_features: ?[]const u8 = null,
     progress_node: std.Progress.Node = .none,
     skip_log_cmdline_on_compile_errors: bool = false,
+    /// If this is provided, compilation errors are sent here. Otherwise, they are printed to stderr.
+    /// Must be an initialized `ErrorBundle`; if it is updated then it is cleared first.
+    error_bundle: ?*ErrorBundle = null,
 };
 pub const BuildExeSubprocessError = error{
 @@ -1781,8 +1784,10 @@ pub fn buildExeSubprocess(
     var result: ?Cache.Path = null;
     defer if (result) |r| gpa.free(r.sub_path);
-    var result_error_bundle: ErrorBundle = .empty;
+    var default_error_bundle: ErrorBundle = .empty;
-    defer result_error_bundle.deinit(gpa);
+    defer default_error_bundle.deinit(gpa);
+    const error_bundle = options.error_bundle orelse &default_error_bundle;
     var received_fs_inputs = false;
     var cache_hit = false;
 @@ -1816,8 +1821,8 @@ pub fn buildExeSubprocess(
                 }
             },
             .error_bundle => {
-                result_error_bundle.deinit(gpa);
+                error_bundle.deinit(gpa);
-                result_error_bundle = Server.allocErrorBundle(gpa, body) catch |err| switch (err) {
+                error_bundle.* = Server.allocErrorBundle(gpa, body) catch |err| switch (err) {
                     error.EndOfStream => break,
                     else => |e| return e,
                 };
 @@ -1884,8 +1889,8 @@ pub fn buildExeSubprocess(
         return error.AlreadyReported;
     }
-    if (result_error_bundle.errorMessageCount() > 0) {
+    if (default_error_bundle.errorMessageCount() > 0) {
-        result_error_bundle.renderToStderr(io, .{}, .auto) catch |err| switch (err) {
+        default_error_bundle.renderToStderr(io, .{}, .auto) catch |err| switch (err) {
             error.Canceled => |e| return e,
             else => |e| {
                 log.err("failed rendering error bundle: {t}", .{e});
 @@ -1893,12 +1898,17 @@ pub fn buildExeSubprocess(
             },
         };
         if (!options.skip_log_cmdline_on_compile_errors) log.err("command reported {d} compilation errors: {f}", .{
-            result_error_bundle.errorMessageCount(), cmd,
+            default_error_bundle.errorMessageCount(), cmd,
         });
         if (received_fs_inputs) return error.FailedButCacheIntact;
         return error.AlreadyReported;
     }
+    if (error_bundle.errorMessageCount() > 0) {
+        if (received_fs_inputs) return error.FailedButCacheIntact;
+        return error.AlreadyReported;
+    }
     const base_path = result orelse {
         log.err("command failed to report result: {f}", .{cmd});
         return error.AlreadyReported;

lib/std/zig/Server.zig+8-22

 @@ -83,6 +83,10 @@ pub const Message = struct {
         /// Body is a cwd relative path to the configuration file.
         /// This message only applies to the build system protocol.
         bsp_configuration,
+        /// build.zig itself failed to build from source.
+        /// Body is an `ErrorBundle`
+        /// This message only applies to the build system protocol.
+        bsp_configuration_failed,
         /// Does not have a body.
         /// This message only applies to the build system protocol.
         bsp_build_started,
 @@ -307,7 +311,7 @@ pub fn serveTestResults(s: *Server, msg: OutMessage.TestResults) !void {
     try s.out.flush();
 }
-pub fn serveErrorBundle(s: *Server, error_bundle: std.zig.ErrorBundle) !void {
+pub fn serveErrorBundle(s: *Server, tag: Message.Tag, error_bundle: std.zig.ErrorBundle) !void {
     const eb_hdr: OutMessage.ErrorBundle = .{
         .extra_len = @intCast(error_bundle.extra.len),
         .string_bytes_len = @intCast(error_bundle.string_bytes.len),
 @@ -315,7 +319,7 @@ pub fn serveErrorBundle(s: *Server, error_bundle: std.zig.ErrorBundle) !void {
     const bytes_len = @sizeOf(OutMessage.ErrorBundle) +
         4 * error_bundle.extra.len + error_bundle.string_bytes.len;
     try s.serveMessageHeader(.{
-        .tag = .error_bundle,
+        .tag = tag,
         .bytes_len = @intCast(bytes_len),
     });
     try s.out.writeStruct(eb_hdr, .little);
 @@ -327,31 +331,13 @@ pub fn serveErrorBundle(s: *Server, error_bundle: std.zig.ErrorBundle) !void {
 pub fn allocErrorBundle(gpa: Allocator, body: []const u8) error{ OutOfMemory, EndOfStream }!std.zig.ErrorBundle {
     var r: Reader = .fixed(body);
     const hdr = r.takeStruct(OutMessage.ErrorBundle, .little) catch |err| switch (err) {
-        error.EndOfStream => |e| return e,
         error.ReadFailed => unreachable,
-    };
-    var eb: std.zig.ErrorBundle = .{
-        .string_bytes = &.{},
-        .extra = &.{},
-    };
-    errdefer eb.deinit(gpa);
-    const extra = try gpa.alloc(u32, hdr.extra_len);
-    eb.extra = extra;
-    const string_bytes = try gpa.alloc(u8, hdr.string_bytes_len);
-    eb.string_bytes = string_bytes;
-    r.readSliceEndian(u32, extra, .little) catch |err| switch (err) {
         error.EndOfStream => |e| return e,
-        error.ReadFailed => unreachable,
     };
-    r.readSliceAll(string_bytes) catch |err| switch (err) {
+    return std.zig.ErrorBundle.readAlloc(&r, gpa, hdr.extra_len, hdr.string_bytes_len) catch |err| switch (err) {
-        error.EndOfStream => |e| return e,
         error.ReadFailed => unreachable,
+        else => |e| return e,
     };
-    return eb;
 }
 pub const TestMetadata = struct {

tools/bsp.zig+21-37

 @@ -7,6 +7,7 @@ const Configuration = std.Build.Configuration;
 const Client = std.zig.Client;
 const Server = std.zig.Server;
 const log = std.log.scoped(.bsp);
+const panic = std.debug.panic;
 pub fn main(init: std.process.Init) !void {
     const io = init.io;
 @@ -32,7 +33,7 @@ pub fn main(init: std.process.Init) !void {
         .stdin = .pipe,
         .stdout = .pipe,
         .stderr = .pipe,
-    }) catch |err| std.debug.panic("failed to spawn process: {}", .{err});
+    }) catch |err| panic("failed to spawn process: {}", .{err});
     errdefer child_process.kill(io);
     var multi_reader_buffer: Io.File.MultiReader.Buffer(2) = undefined;
 @@ -66,10 +67,10 @@ pub fn main(init: std.process.Init) !void {
                 },
             };
             const body = client_stdout.take(header.bytes_len) catch unreachable;
-            log.debug("received {f} ({d} bytes)", .{ fmtEnum(header.tag), body.len });
+            log.debug("received {} ({d} bytes)", .{ header.tag, body.len });
             if (header.tag != .bsp_handshake) {
-                log.err("received unexpected message: {f}", .{fmtEnum(header.tag)});
+                log.err("received unexpected message: {}", .{header.tag});
                 return error.UnexpectedMessage;
             }
 @@ -94,17 +95,26 @@ pub fn main(init: std.process.Init) !void {
             const body = client_stdout.take(header.bytes_len) catch unreachable;
             log.debug("received {t} ({d} bytes)", .{ header.tag, body.len });
-            if (header.tag != .bsp_configuration) {
+            switch (header.tag) {
-                log.err("received unexpected message: {f}", .{fmtEnum(header.tag)});
+                .bsp_configuration => {},
-                return error.UnexpectedMessage;
+                .bsp_configuration_failed => {
+                    var eb = try Server.allocErrorBundle(gpa, body);
+                    defer eb.deinit(gpa);
+                    try eb.renderToStderr(io, .{}, .auto);
+                    panic("configuration failed", .{});
+                },
+                else => {
+                    log.err("received unexpected message: {}", .{header.tag});
+                    return error.UnexpectedMessage;
+                },
             }
             const configuration_path = body;
             var file = Io.Dir.cwd().openFile(io, configuration_path, .{}) catch |err|
-                std.debug.panic("failed to open configuration file {q}: {t}", .{ configuration_path, err });
+                panic("failed to open configuration file {q}: {t}", .{ configuration_path, err });
             defer file.close(io);
             break :configuration Configuration.loadFile(conf_arena, io, file) catch |err|
-                std.debug.panic("failed to load configuration file {q}: {t}", .{ configuration_path, err });
+                panic("failed to load configuration file {q}: {t}", .{ configuration_path, err });
         };
         const c = &configuration;
 @@ -157,7 +167,7 @@ pub fn main(init: std.process.Init) !void {
                             if (std.fmt.parseInt(u32, arg, 10)) |i|
                                 @fromBackingInt(i)
                             else |_|
-                                top_level_steps.get(arg) orelse std.debug.panic("unexpected step name or index", .{});
+                                top_level_steps.get(arg) orelse panic("unexpected step name or index", .{});
                         try steps.append(gpa, step);
                     }
                 }
 @@ -178,7 +188,7 @@ pub fn main(init: std.process.Init) !void {
                         },
                     };
                     const body = client_stdout.take(header.bytes_len) catch unreachable;
-                    log.debug("received {f} ({d} bytes)", .{ fmtEnum(header.tag), body.len });
+                    log.debug("received {} ({d} bytes)", .{ header.tag, body.len });
                     switch (header.tag) {
                         .bsp_build_started => {},
 @@ -214,7 +224,7 @@ pub fn main(init: std.process.Init) !void {
                             }
                         },
                         .bsp_configuration => @panic("TODO"),
-                        else => std.debug.panic("received unexpected message: {f}", .{fmtEnum(header.tag)}),
+                        else => panic("received unexpected message: {}", .{header.tag}),
                     }
                 }
                 continue;
 @@ -242,29 +252,3 @@ pub fn main(init: std.process.Init) !void {
         log.err("maker {f}", .{term});
     }
 }
-const FormatEnum = union(enum) {
-    named: []const u8,
-    unnamed: usize,
-    pub fn format(
-        e: FormatEnum,
-        writer: *std.Io.Writer,
-    ) std.Io.Writer.Error!void {
-        switch (e) {
-            .named => |name| {
-                try writer.writeByte('.');
-                try writer.writeAll(name);
-            },
-            .unnamed => |number| try writer.print("0x{x}", .{number}),
-        }
-    }
-};
-fn fmtEnum(e: anytype) FormatEnum {
-    if (std.enums.tagName(@TypeOf(e), e)) |name| {
-        return .{ .named = name };
-    } else {
-        return .{ .unnamed = @backingInt(e) };
-    }
-}

...	@@ -740,6 +740,9 @@ pub fn main(init: process.Init.Minimal) !void {	...	@@ -740,6 +740,9 @@ pub fn main(init: process.Init.Minimal) !void {
740	var configure_source_files: Cache.Manifest.SelfContainedFiles = .empty;	740	var configure_source_files: Cache.Manifest.SelfContainedFiles = .empty;
741	defer configure_source_files.deinit(gpa);	741	defer configure_source_files.deinit(gpa);
742		742
		743	var configure_error_bundle: std.zig.ErrorBundle = .empty;
		744	defer configure_error_bundle.deinit(gpa);
		745
743	// If this fails, we can still start the server and wait for user	746	// If this fails, we can still start the server and wait for user
744	// to request a rebuild. If it returns error.FailedButCacheIntact	747	// to request a rebuild. If it returns error.FailedButCacheIntact
745	// we can even still do file system watching and automatically	748	// we can even still do file system watching and automatically
...	@@ -762,6 +765,7 @@ pub fn main(init: process.Init.Minimal) !void {	...	@@ -762,6 +765,7 @@ pub fn main(init: process.Init.Minimal) !void {
762	.print_configuration = print_configuration,	765	.print_configuration = print_configuration,
763	.forks = forks.items,	766	.forks = forks.items,
764	.src_files = &configure_source_files,	767	.src_files = &configure_source_files,
		768	.error_bundle = if (protocol_server != null) &configure_error_bundle else null,
765	})) \|scanned_config\| {	769	})) \|scanned_config\| {
766	if (help_menu) {	770	if (help_menu) {
767	scanned_config.printUsage(&graph, initStdoutWriter(io)) catch \|err\| switch (err) {	771	scanned_config.printUsage(&graph, initStdoutWriter(io)) catch \|err\| switch (err) {
...	@@ -1048,8 +1052,8 @@ pub fn main(init: process.Init.Minimal) !void {	...	@@ -1048,8 +1052,8 @@ pub fn main(init: process.Init.Minimal) !void {
1048	_ = io.lockStderr(&.{}, graph.stderr_mode) catch {};	1052	_ = io.lockStderr(&.{}, graph.stderr_mode) catch {};
1049	process.exit(1);	1053	process.exit(1);
1050	}	1054	}
1051	if (protocol_server != null) {	1055	if (protocol_server) \|s\| {
1052	fatal("(zig build system) TODO send error messages to client when build.zig compilation fails", .{});	1056	try s.serveErrorBundle(.bsp_configuration_failed, configure_error_bundle);
1053	}	1057	}
1054	if (watch_flag and can_fs_watch) {	1058	if (watch_flag and can_fs_watch) {
1055	fatal("(zig build system) TODO set up fs watching even when build.zig compilation fails", .{});	1059	fatal("(zig build system) TODO set up fs watching even when build.zig compilation fails", .{});
...	@@ -1087,6 +1091,7 @@ const ConfigureOptions = struct {	...	@@ -1087,6 +1091,7 @@ const ConfigureOptions = struct {
1087	print_configuration: PrintConfiguration,	1091	print_configuration: PrintConfiguration,
1088	forks: []Fork,	1092	forks: []Fork,
1089	src_files: *Cache.Manifest.SelfContainedFiles,	1093	src_files: *Cache.Manifest.SelfContainedFiles,
		1094	error_bundle: ?*std.zig.ErrorBundle = null,
1090	};	1095	};
1091		1096
1092	fn configure(graph: *Graph, options: ConfigureOptions) !ScannedConfig {	1097	fn configure(graph: *Graph, options: ConfigureOptions) !ScannedConfig {
...	@@ -1471,6 +1476,7 @@ fn configure(graph: *Graph, options: ConfigureOptions) !ScannedConfig {	...	@@ -1471,6 +1476,7 @@ fn configure(graph: *Graph, options: ConfigureOptions) !ScannedConfig {
1471	.arch_os_abi = target_arch_os_abi,	1476	.arch_os_abi = target_arch_os_abi,
1472	.progress_node = compile_prog_node,	1477	.progress_node = compile_prog_node,
1473	.skip_log_cmdline_on_compile_errors = !graph.verbose,	1478	.skip_log_cmdline_on_compile_errors = !graph.verbose,
		1479	.error_bundle = options.error_bundle,
1474	})) \|r\| r.path else \|err\| return err;	1480	})) \|r\| r.path else \|err\| return err;
1475	defer gpa.free(configure_exe_path.sub_path);	1481	defer gpa.free(configure_exe_path.sub_path);
1476		1482