diff --git a/lang/spidermonkey78/files/patch-build_moz.configure_flags.configure b/lang/spidermonkey78/files/patch-build_moz.configure_flags.configure
new file mode 100644
index 0000000000000..24b8f65c80e8c
--- /dev/null
+++ b/lang/spidermonkey78/files/patch-build_moz.configure_flags.configure
@@ -0,0 +1,11 @@
+--- build/moz.configure/flags.configure.orig	2023-06-24 10:37:11 UTC
++++ build/moz.configure/flags.configure
+@@ -56,7 +56,7 @@ def new_pass_manager_flags(enabled, compiler, host, ta
+         # Temporary until https://bugs.llvm.org/show_bug.cgi?id=45835 gets a
+         # real fix: clang 10 hangs with some ubsan-inserted code constructs.
+         return None
+-    if enabled and compiler.version >= '9.0.0':
++    if enabled and compiler.version >= '9.0.0' and compiler.version < '16.0.0':
+         if compiler.type == 'clang':
+             return ['-fexperimental-new-pass-manager']
+         elif compiler.type == 'clang-cl':
diff --git a/lang/spidermonkey78/files/patch-python_mozbuild_mozbuild_util.py b/lang/spidermonkey78/files/patch-python_mozbuild_mozbuild_util.py
index 3c5488327fd83..1f91ba15f4c12 100644
--- a/lang/spidermonkey78/files/patch-python_mozbuild_mozbuild_util.py
+++ b/lang/spidermonkey78/files/patch-python_mozbuild_mozbuild_util.py
@@ -1,4 +1,4 @@
---- python/mozbuild/mozbuild/util.py.orig	2021-03-15 15:52:38 UTC
+--- python/mozbuild/mozbuild/util.py.orig	2021-09-28 10:04:57 UTC
 +++ python/mozbuild/mozbuild/util.py
 @@ -27,6 +27,11 @@ from collections import (
  )
@@ -12,6 +12,15 @@
  import six
  
  if sys.platform == 'win32':
+@@ -220,7 +225,7 @@ class FileAvoidWrite(BytesIO):
+     still occur, as well as diff capture if requested.
+     """
+ 
+-    def __init__(self, filename, capture_diff=False, dry_run=False, readmode='rU'):
++    def __init__(self, filename, capture_diff=False, dry_run=False, readmode='r'):
+         BytesIO.__init__(self)
+         self.name = filename
+         assert type(capture_diff) == bool
 @@ -782,7 +787,7 @@ class HierarchicalStringList(object):
          self._strings = StrictOrderingOnAppendList()
          self._children = {}