From caf924a0f26307e19d9fb261a230136ee80bb0ee Mon Sep 17 00:00:00 2001
From: David Zbarsky <zbarsky@openai.com>
Date: Sun, 29 Mar 2026 14:04:07 -0400
Subject: [PATCH] foo

---
 MODULE.bazel                                  |  2 ++
 patches/BUILD.bazel                           |  1 +
 ...lchains_llvm_trim_mingw_msvcrt_patch.patch | 29 +++++++++++++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 patches/toolchains_llvm_trim_mingw_msvcrt_patch.patch

diff --git a/MODULE.bazel b/MODULE.bazel
index e71f92ca77..62e735929a 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -11,8 +11,10 @@ single_version_override(
     patch_strip = 1,
     patches = [
         "//patches:llvm_windows_symlink_extract.patch",
+        "//patches:toolchains_llvm_trim_mingw_msvcrt_patch.patch",
     ],
 )
+
 # Abseil picks a MinGW pthread TLS path that does not match our hermetic
 # windows-gnullvm toolchain; force it onto the portable C++11 thread-local path.
 single_version_override(
diff --git a/patches/BUILD.bazel b/patches/BUILD.bazel
index 8d4acbbb91..09f12dc899 100644
--- a/patches/BUILD.bazel
+++ b/patches/BUILD.bazel
@@ -5,6 +5,7 @@ exports_files([
     "rules_rust_windows_gnullvm_build_script.patch",
     "rules_rs_windows_gnullvm_exec.patch",
     "rusty_v8_prebuilt_out_dir.patch",
+    "toolchains_llvm_trim_mingw_msvcrt_patch.patch",
     "v8_bazel_rules.patch",
     "v8_module_deps.patch",
     "v8_source_portability.patch",
diff --git a/patches/toolchains_llvm_trim_mingw_msvcrt_patch.patch b/patches/toolchains_llvm_trim_mingw_msvcrt_patch.patch
new file mode 100644
index 0000000000..71a2c4a2b4
--- /dev/null
+++ b/patches/toolchains_llvm_trim_mingw_msvcrt_patch.patch
@@ -0,0 +1,29 @@
+diff --git a/runtimes/mingw/extension/mingw.bzl b/runtimes/mingw/extension/mingw.bzl
+--- a/runtimes/mingw/extension/mingw.bzl
++++ b/runtimes/mingw/extension/mingw.bzl
+@@ -11,7 +11,7 @@ def _mingw_extension_impl(module_ctx):
+         strip_prefix = "mingw-w64-v13.0.0",
+         build_file = "//runtimes/mingw:mingw.BUILD.bazel",
+         patches = [
+-            "//runtimes/mingw/patches:remove-fpreset-from-msvcrt-def.patch",
++            "//runtimes/mingw/patches:remove-fpreset-from-msvcrt-def-single-hunk.patch",
+         ],
+         patch_args = ["-p1"],
+     )
+diff --git a/runtimes/mingw/patches/remove-fpreset-from-msvcrt-def-single-hunk.patch b/runtimes/mingw/patches/remove-fpreset-from-msvcrt-def-single-hunk.patch
+new file mode 100644
+--- /dev/null
++++ b/runtimes/mingw/patches/remove-fpreset-from-msvcrt-def-single-hunk.patch
+@@ -0,0 +1,12 @@
++diff --git a/mingw-w64-crt/lib-common/msvcrt.def.in b/mingw-w64-crt/lib-common/msvcrt.def.in
++index 95b25012b..95b25012b 100644
++--- a/mingw-w64-crt/lib-common/msvcrt.def.in
+++++ b/mingw-w64-crt/lib-common/msvcrt.def.in
++@@ -603,7 +603,6 @@
++ _fmode DATA
++ _fpclass
++ F_NON_X64(_fpieee_flt)
++-_fpreset F_LD80(DATA)
++ _fputchar
++ _fputwchar
++ _fsopen