Start time performance improvements to build tools (#3797)

* Make os.cpus() faster on Linux

* Fix crash

See https://github.com/ziglang/zig/issues/16540

* Handle watcher_count == 0

* Add assertion

* Clean up lifetimes of fs watcher a little

* :scissors:

* Use `errdefer`

* Make the error better

* Make os.cpus() more lazy

* Please don't translate-c on the entire C standard library

* immediately closing works correctly is still bug

* ops

* fmt+fixeup

* add back verbose

* free instead of destroy

* remove destroy option for watcher tasks

* flush verbose and add debug log

* fixup files

* use log for debug

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>
Co-authored-by: cirospaciari <ciro.spaciari@gmail.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/bun.js/node/node_fs.zig b/src/bun.js/node/node_fs.zig
index 8fb769fac..314cd44bd 100644
--- a/src/bun.js/node/node_fs.zig
+++ b/src/bun.js/node/node_fs.zig
@@ -4488,8 +4488,13 @@ pub const NodeFS = struct {
     }
     pub fn watch(_: *NodeFS, args: Arguments.Watch, comptime _: Flavor) Maybe(Return.Watch) {
         const watcher = args.createFSWatcher() catch |err| {
-            args.global_this.throwError(err, "Failed to watch filename");
-            return Maybe(Return.Watch){ .result = JSC.JSValue.jsUndefined() };
+            var buf = std.fmt.allocPrint(bun.default_allocator, "{s} watching {}", .{ @errorName(err), strings.QuotedFormatter{ .text = args.path.slice() } }) catch unreachable;
+            defer bun.default_allocator.free(buf);
+            args.global_this.throwValue((JSC.SystemError{
+                .message = bun.String.init(buf),
+                .path = bun.String.init(args.path.slice()),
+            }).toErrorInstance(args.global_this));
+            return Maybe(Return.Watch){ .result = JSC.JSValue.undefined };
         };
         return Maybe(Return.Watch){ .result = watcher };
     }