From c3b09e4f29f5dbb82708b73e5730be4e2d9ebf2f Mon Sep 17 00:00:00 2001
From: Nick Roberts <nroberts@janestreet.com>
Date: Fri, 8 Dec 2023 17:16:40 -0500
Subject: [PATCH 1/2] Enable warn-error by default

---
 ocaml/configure    | 12 +++++++-----
 ocaml/configure.ac |  9 +++++----
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/ocaml/configure b/ocaml/configure
index 23472daf252..e1e8e56d448 100755
--- a/ocaml/configure
+++ b/ocaml/configure
@@ -1632,7 +1632,7 @@ Optional Features:
                           headers
   --disable-stdlib-manpages
                           do not build or install the library man pages
-  --enable-warn-error     treat C compiler warnings as errors
+  --disable-warn-error    do not treat C compiler warnings as errors
   --disable-flat-float-array
                           do not use flat float arrays
   --disable-function-sections
@@ -13646,8 +13646,8 @@ lib_dynlink=true
 
 if test x"$enable_runtime5" = x"yes"
 then :
-  otherlibraries = "$otherlibraries runtime_events"
-   lib_runtime_events = true
+  otherlibraries="$otherlibraries runtime_events"
+   lib_runtime_events=true
 fi
 
 if test x"$enable_unix_lib" != "xno"
@@ -13767,8 +13767,10 @@ case $ocaml_cv_cc_vendor in #(
 -Wold-style-definition" ;;
 esac
 
-case $enable_warn_error,false in #(
-  yes,*|,true) :
+case $enable_warn_error in #(
+  no) :
+     ;; #(
+  *) :
     cc_warnings="$cc_warnings $warn_error_flag" ;; #(
   *) :
      ;;
diff --git a/ocaml/configure.ac b/ocaml/configure.ac
index 35c2a2ab679..2b09175cdc4 100644
--- a/ocaml/configure.ac
+++ b/ocaml/configure.ac
@@ -474,8 +474,8 @@ AC_ARG_ENABLE([stdlib-manpages],
     [do not build or install the library man pages])])
 
 AC_ARG_ENABLE([warn-error],
-  [AS_HELP_STRING([--enable-warn-error],
-    [treat C compiler warnings as errors])])
+  [AS_HELP_STRING([--disable-warn-error],
+    [do not treat C compiler warnings as errors])])
 
 AC_ARG_VAR([WINDOWS_UNICODE_MODE],
   [how to handle Unicode under Windows: ansi, compatible])
@@ -750,8 +750,9 @@ AS_CASE([$ocaml_cv_cc_vendor],
   cc_warnings="-Wall -Wno-pragmas -Wint-conversion -Wstrict-prototypes \
 -Wold-style-definition"])
 
-AS_CASE([$enable_warn_error,OCAML__DEVELOPMENT_VERSION],
-  [yes,*|,true],
+AS_CASE([$enable_warn_error],
+  [no], [],
+  [*],
     [cc_warnings="$cc_warnings $warn_error_flag"])
 
 # We select high optimization levels, provided we can turn off:

From e86e76d0e3dcc421a7ce869ad434bfae2f76aa6f Mon Sep 17 00:00:00 2001
From: Nick Roberts <nroberts@janestreet.com>
Date: Mon, 11 Dec 2023 12:25:55 -0500
Subject: [PATCH 2/2] disable warn error on mac os

---
 .github/workflows/build.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c627f76779d..82ad962b7fe 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -57,7 +57,7 @@ jobs:
             build_ocamlparam: _,ocamlcfg=0
 
           - name: flambda2_macos
-            config: --enable-middle-end=flambda2
+            config: --enable-middle-end=flambda2 --disable-warn-error
             os: macos-latest
 
           - name: irc