From 594b3faaa34f6f464a5c543489cf57fb89070999 Mon Sep 17 00:00:00 2001
From: kcbanner <kcbanner@gmail.com>
Date: Tue, 23 Jun 2026 22:06:17 -0400
Subject: [PATCH] MappedFile: explicitly write the mtime when flushing, as
 mapped file writes don't do this automatically on windows

---
 src/link/MappedFile.zig | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/link/MappedFile.zig b/src/link/MappedFile.zig
index 03b92315aa32ebf8a9baa8a4960354292a5d4634..74c1ce432999043d8fe5ad0331d8ba4128973abd 100644
--- a/src/link/MappedFile.zig
+++ b/src/link/MappedFile.zig
@@ -1314,11 +1314,12 @@ pub fn unmap(mf: *MappedFile) void {
 }
 
 pub fn flush(mf: *MappedFile) (Io.Cancelable || error{MappedFileIo})!void {
-    mf.memory_map.write(mf.io) catch |err| switch (err) {
+    mf.flushInner() catch |err| switch (err) {
         error.Canceled => |e| return e,
 
         error.WouldBlock, // file was not opened as non-blocking
         error.NotOpenForWriting, // we definitely opened the file for writing
+        error.ReadOnlyFileSystem,
         => {
             mf.io_err = error.Unexpected;
             return error.MappedFileIo;
@@ -1331,6 +1332,11 @@ pub fn flush(mf: *MappedFile) (Io.Cancelable || error{MappedFileIo})!void {
     };
 }
 
+fn flushInner(mf: *MappedFile) (Io.File.WritePositionalError || Io.File.SetTimestampsError)!void {
+    try mf.memory_map.write(mf.io);
+    if (is_windows) try mf.memory_map.file.setTimestampsNow(mf.io);
+}
+
 fn verify(mf: *MappedFile) void {
     const root = Node.Index.root.get(mf);
     assert(root.parent == .none);
-- 
2.54.0