From c2bf11e6011b1e78024839e3810f79bf1dd5c1d5 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 01/22] [mypyc] feat: improve LoadLiteral annotation
 determinism

---
 mypyc/codegen/emit.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 4ef53296ef0d..df9d8c8143c1 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -208,6 +208,15 @@ def object_annotation(self, obj: object, line: str) -> str:
         if any(x in formatted for x in ("/*", "*/", "\0")):
             return ""
 
+        # make frozenset annotations deterministic
+        if formatted.startswith("frozenset({"):
+            frozenset_items = formatted[11:-2]
+            # if our frozenset contains another frozenset or a tuple, we will need better logic
+            # here, but this redimentary logic will still vastly improve codegen determinism.
+            if "(" not in frozenset_items:
+                sorted_items = ", ".join(sorted(frozenset_items.split(", ")))
+                formatted = "frozenset({" + sorted_items + "})"
+
         if "\n" in formatted:
             first_line, rest = formatted.split("\n", maxsplit=1)
             comment_continued = textwrap.indent(rest, (line_width + 3) * " ")

From d750ec12df4d4696288c3905eb9cbcec8c749afa Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 02/22] Update emit.py

---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index df9d8c8143c1..c8706f19e548 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -212,7 +212,7 @@ def object_annotation(self, obj: object, line: str) -> str:
         if formatted.startswith("frozenset({"):
             frozenset_items = formatted[11:-2]
             # if our frozenset contains another frozenset or a tuple, we will need better logic
-            # here, but this redimentary logic will still vastly improve codegen determinism.
+            # here, but this rudimentary logic will still vastly improve codegen determinism.
             if "(" not in frozenset_items:
                 sorted_items = ", ".join(sorted(frozenset_items.split(", ")))
                 formatted = "frozenset({" + sorted_items + "})"

From 486f9f01b253c31bbd0b2b3faa227adc820c691a Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 03/22] new sort key

---
 mypyc/codegen/emit.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index c8706f19e548..e33b39c48095 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1235,3 +1235,11 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
     # Multi-line result
     res.append(indent + ", ".join(current))
     return "{\n    " + ",\n    ".join(res) + "\n" + indent + "}"
+
+
+class _mypyc_safe_key(pprint._safe_key):
+    """A custom sort key implementation for pprint that makes the output deterministic
+    for all literal types supported by mypyc
+    """
+    def __lt__(self, other: "_mypyc_safe_key") -> bool:
+        return str(type(self.obj)) + repr(self.obj) < str(type(other.obj)) + repr(other.obj)

From c30a72735180daed5e5b141dc95fa6e35f58b444 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 04/22] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypyc/codegen/emit.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index e33b39c48095..10b831be5623 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1241,5 +1241,6 @@ class _mypyc_safe_key(pprint._safe_key):
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc
     """
-    def __lt__(self, other: "_mypyc_safe_key") -> bool:
+
+    def __lt__(self, other: _mypyc_safe_key) -> bool:
         return str(type(self.obj)) + repr(self.obj) < str(type(other.obj)) + repr(other.obj)

From d174f4eeb3538ef046c05a79c44a975bc8c321ee Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 05/22] use new safe key

---
 mypyc/codegen/emit.py | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 10b831be5623..ac4ccb665f48 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -204,19 +204,20 @@ def object_annotation(self, obj: object, line: str) -> str:
 
         If it contains illegal characters, an empty string is returned."""
         line_width = self._indent + len(line)
+
+        # temporarily override pprint._safe_key
+        default_safe_key = pprint._safe_key
+        pprint._safe_key = _mypyc_safe_key
+
+        # pretty print the object
         formatted = pprint.pformat(obj, compact=True, width=max(90 - line_width, 20))
+
+        # replace the _safe_key
+        pprint._safe_key = default_safe_key
+        
         if any(x in formatted for x in ("/*", "*/", "\0")):
             return ""
 
-        # make frozenset annotations deterministic
-        if formatted.startswith("frozenset({"):
-            frozenset_items = formatted[11:-2]
-            # if our frozenset contains another frozenset or a tuple, we will need better logic
-            # here, but this rudimentary logic will still vastly improve codegen determinism.
-            if "(" not in frozenset_items:
-                sorted_items = ", ".join(sorted(frozenset_items.split(", ")))
-                formatted = "frozenset({" + sorted_items + "})"
-
         if "\n" in formatted:
             first_line, rest = formatted.split("\n", maxsplit=1)
             comment_continued = textwrap.indent(rest, (line_width + 3) * " ")
@@ -1239,8 +1240,10 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
 
 class _mypyc_safe_key(pprint._safe_key):
     """A custom sort key implementation for pprint that makes the output deterministic
-    for all literal types supported by mypyc
-    """
+    for all literal types supported by mypyc.
 
-    def __lt__(self, other: _mypyc_safe_key) -> bool:
+    This is NOT safe for use as a sort key for other types, so we MUST replace the
+    original pprint._safe_key once we've pprinted our object.
+    """
+    def __lt__(self, other: "_mypyc_safe_key") -> bool:
         return str(type(self.obj)) + repr(self.obj) < str(type(other.obj)) + repr(other.obj)

From 28c0399bd04939af69a1445de0d34ea845b89556 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 06/22] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypyc/codegen/emit.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index ac4ccb665f48..1d8b8ef5022f 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -214,7 +214,7 @@ def object_annotation(self, obj: object, line: str) -> str:
 
         # replace the _safe_key
         pprint._safe_key = default_safe_key
-        
+
         if any(x in formatted for x in ("/*", "*/", "\0")):
             return ""
 
@@ -1245,5 +1245,6 @@ class _mypyc_safe_key(pprint._safe_key):
     This is NOT safe for use as a sort key for other types, so we MUST replace the
     original pprint._safe_key once we've pprinted our object.
     """
-    def __lt__(self, other: "_mypyc_safe_key") -> bool:
+
+    def __lt__(self, other: _mypyc_safe_key) -> bool:
         return str(type(self.obj)) + repr(self.obj) < str(type(other.obj)) + repr(other.obj)

From be0de786c953ed44bc8d964de28be1ac016321aa Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 07/22] Update emit.py

---
 mypyc/codegen/emit.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 1d8b8ef5022f..849322ef26e9 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -206,14 +206,14 @@ def object_annotation(self, obj: object, line: str) -> str:
         line_width = self._indent + len(line)
 
         # temporarily override pprint._safe_key
-        default_safe_key = pprint._safe_key
-        pprint._safe_key = _mypyc_safe_key
+        default_safe_key = pprint._safe_key  # type: ignore [attr-defined]
+        pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
 
         # pretty print the object
         formatted = pprint.pformat(obj, compact=True, width=max(90 - line_width, 20))
 
         # replace the _safe_key
-        pprint._safe_key = default_safe_key
+        pprint._safe_key = default_safe_key  # type: ignore [attr-defined]
 
         if any(x in formatted for x in ("/*", "*/", "\0")):
             return ""
@@ -1238,7 +1238,7 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
     return "{\n    " + ",\n    ".join(res) + "\n" + indent + "}"
 
 
-class _mypyc_safe_key(pprint._safe_key):
+def _mypyc_safe_key(pprint._safe_key):  # type: ignore [attr-defined, misc]
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc.
 

From d33d2d979cfab684058ac968f5afdd4cc8de15fb Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 08/22] Update emit.py

---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 849322ef26e9..394ae0d11644 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1238,7 +1238,7 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
     return "{\n    " + ",\n    ".join(res) + "\n" + indent + "}"
 
 
-def _mypyc_safe_key(pprint._safe_key):  # type: ignore [attr-defined, misc]
+class _mypyc_safe_key(pprint._safe_key):  # type: ignore [attr-defined, misc]
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc.
 

From 650d99d6b74e5433de399f7231d07cd7054dd3bb Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 09/22] Update emit.py

---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 394ae0d11644..f2bc07d6587f 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1238,7 +1238,7 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
     return "{\n    " + ",\n    ".join(res) + "\n" + indent + "}"
 
 
-class _mypyc_safe_key(pprint._safe_key):  # type: ignore [attr-defined, misc]
+class _mypyc_safe_key(pprint._safe_key):  # type: ignore [attr-defined, name-defined, misc]
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc.
 

From da2278578d3431b5dcf8ba9f1360aa3e4bb31ccd Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 10/22] Update emit.py

---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index f2bc07d6587f..24df8e6ecf00 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1238,7 +1238,7 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
     return "{\n    " + ",\n    ".join(res) + "\n" + indent + "}"
 
 
-class _mypyc_safe_key(pprint._safe_key):  # type: ignore [attr-defined, name-defined, misc]
+class _mypyc_safe_key(pprint._safe_key):  # type: ignore [name-defined, misc]
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc.
 

From 96aa63e6818ce44da0d0da724523d37d2da185fc Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:00:41 +0000
Subject: [PATCH 11/22] refactor

---
 mypyc/codegen/emit.py | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 24df8e6ecf00..9db22cc75c79 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1238,13 +1238,11 @@ def c_array_initializer(components: list[str], *, indented: bool = False) -> str
     return "{\n    " + ",\n    ".join(res) + "\n" + indent + "}"
 
 
-class _mypyc_safe_key(pprint._safe_key):  # type: ignore [name-defined, misc]
+def _mypyc_safe_key(obj: object) -> str:
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc.
 
     This is NOT safe for use as a sort key for other types, so we MUST replace the
     original pprint._safe_key once we've pprinted our object.
     """
-
-    def __lt__(self, other: _mypyc_safe_key) -> bool:
-        return str(type(self.obj)) + repr(self.obj) < str(type(other.obj)) + repr(other.obj)
+    return str(type(obj)) + repr(obj)

From 58e4b6752ff39e15dcb4634db3f94c46207831ab Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 7 Oct 2025 12:32:40 -0400
Subject: [PATCH 12/22] Update emit.py

---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 9db22cc75c79..ebb152923ff6 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1245,4 +1245,4 @@ def _mypyc_safe_key(obj: object) -> str:
     This is NOT safe for use as a sort key for other types, so we MUST replace the
     original pprint._safe_key once we've pprinted our object.
     """
-    return str(type(obj)) + repr(obj)
+    return str(type(obj)) + pprint.pformat(obj)

From 629f1cf99bd7febced2ba9f4f07f6fc045c1f1b3 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 06:11:39 +0000
Subject: [PATCH 13/22] extract func pformat_deterministic

---
 mypyc/codegen/emit.py | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 44f78f6510c3..bb813a6c52fd 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -210,16 +210,7 @@ def object_annotation(self, obj: object, line: str) -> str:
 
         If it contains illegal characters, an empty string is returned."""
         line_width = self._indent + len(line)
-
-        # temporarily override pprint._safe_key
-        default_safe_key = pprint._safe_key  # type: ignore [attr-defined]
-        pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
-
-        # pretty print the object
-        formatted = pprint.pformat(obj, compact=True, width=max(90 - line_width, 20))
-
-        # replace the _safe_key
-        pprint._safe_key = default_safe_key  # type: ignore [attr-defined]
+        formatted = pformat_deterministic(obj, line_width)
 
         if any(x in formatted for x in ("/*", "*/", "\0")):
             return ""
@@ -1283,6 +1274,19 @@ def native_function_doc_initializer(func: FuncIR) -> str:
     return c_string_initializer(docstring.encode("ascii", errors="backslashreplace"))
 
 
+def pformat_deterministic(obj: object, line_width: int) -> str:
+    """Pretty-print `obj` with deterministic sorting for mypyc literal types."""
+    # Temporarily override pprint._safe_key
+    default_safe_key = pprint._safe_key  # type: ignore [attr-defined]
+    pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
+    
+    try:
+        return pprint.pformat(obj, compact=True, width=max(90 - line_width, 20))
+    finally:
+        # Always restore the original key to avoid affecting other pprint users.
+        pprint._safe_key = default_safe_key  # type: ignore [attr-defined]
+
+
 def _mypyc_safe_key(obj: object) -> str:
     """A custom sort key implementation for pprint that makes the output deterministic
     for all literal types supported by mypyc.

From ac8f3ffc15abc90a304d144bfd47fed273b7f73f Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 6 Jan 2026 06:15:37 +0000
Subject: [PATCH 14/22] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index bb813a6c52fd..0631ecd479c0 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1279,7 +1279,7 @@ def pformat_deterministic(obj: object, line_width: int) -> str:
     # Temporarily override pprint._safe_key
     default_safe_key = pprint._safe_key  # type: ignore [attr-defined]
     pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
-    
+
     try:
         return pprint.pformat(obj, compact=True, width=max(90 - line_width, 20))
     finally:

From 866d86e5d46d1ee01edcb52fd022f8969c49a524 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 06:27:51 +0000
Subject: [PATCH 15/22] add tests

---
 mypyc/codegen/emit.py   | 10 +++++-----
 mypyc/test/test_emit.py | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index bb813a6c52fd..a59e4850cd18 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -210,7 +210,7 @@ def object_annotation(self, obj: object, line: str) -> str:
 
         If it contains illegal characters, an empty string is returned."""
         line_width = self._indent + len(line)
-        formatted = pformat_deterministic(obj, line_width)
+        formatted = pformat_deterministic(obj, max(90 - line_width, 20))
 
         if any(x in formatted for x in ("/*", "*/", "\0")):
             return ""
@@ -1274,14 +1274,14 @@ def native_function_doc_initializer(func: FuncIR) -> str:
     return c_string_initializer(docstring.encode("ascii", errors="backslashreplace"))
 
 
-def pformat_deterministic(obj: object, line_width: int) -> str:
+def pformat_deterministic(obj: object, width: int) -> str:
     """Pretty-print `obj` with deterministic sorting for mypyc literal types."""
-    # Temporarily override pprint._safe_key
+    # Temporarily override pprint._safe_key to get deterministic ordering of containers.
     default_safe_key = pprint._safe_key  # type: ignore [attr-defined]
     pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
-    
+
     try:
-        return pprint.pformat(obj, compact=True, width=max(90 - line_width, 20))
+        return pprint.pformat(obj, compact=True, width=width)
     finally:
         # Always restore the original key to avoid affecting other pprint users.
         pprint._safe_key = default_safe_key  # type: ignore [attr-defined]
diff --git a/mypyc/test/test_emit.py b/mypyc/test/test_emit.py
index 1baed3964299..7fef63aa744c 100644
--- a/mypyc/test/test_emit.py
+++ b/mypyc/test/test_emit.py
@@ -1,8 +1,9 @@
 from __future__ import annotations
 
+import pprint
 import unittest
 
-from mypyc.codegen.emit import Emitter, EmitterContext
+from mypyc.codegen.emit import Emitter, EmitterContext, pformat_deterministic
 from mypyc.common import HAVE_IMMORTAL
 from mypyc.ir.class_ir import ClassIR
 from mypyc.ir.ops import BasicBlock, Register, Value
@@ -21,6 +22,37 @@
 from mypyc.namegen import NameGenerator
 
 
+class TestPformatDeterministic(unittest.TestCase):
+    def test_frozenset_elements_sorted(self) -> None:
+        fs_small = frozenset({("a", 1)})
+        fs_large = frozenset({("a", 1), ("b", 2)})
+        literal_a = frozenset({fs_large, fs_small})
+        literal_b = frozenset({fs_small, fs_large})
+        expected = "frozenset({frozenset({('a', 1)}), frozenset({('a', 1), ('b', 2)})})"
+
+        assert pformat_deterministic(literal_a, 80) == expected
+        assert pformat_deterministic(literal_b, 80) == expected
+
+    def test_nested_supported_literals(self) -> None:
+        nested_frozen = frozenset({("m", 0), ("n", 1)})
+        item_a = ("outer", 1, nested_frozen)
+        item_b = ("outer", 2, frozenset({("x", 3)}))
+        literal_a = frozenset({item_a, item_b})
+        literal_b = frozenset({item_b, item_a})
+        expected = (
+            "frozenset({('outer', 1, frozenset({('m', 0), ('n', 1)})), "
+            "('outer', 2, frozenset({('x', 3)}))})"
+        )
+
+        assert pformat_deterministic(literal_a, 120) == expected
+        assert pformat_deterministic(literal_b, 120) == expected
+
+    def test_restores_default_safe_key(self) -> None:
+        original_safe_key = pprint._safe_key
+        pformat_deterministic({"key": "value"}, 80)
+        assert pprint._safe_key is original_safe_key
+
+
 class TestEmitter(unittest.TestCase):
     def setUp(self) -> None:
         self.n = Register(int_rprimitive, "n")

From 6e0153a749f03fb6a8a9372aa6e6c87571744e57 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 06:49:32 +0000
Subject: [PATCH 16/22] fix test

---
 mypyc/test/test_emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/test/test_emit.py b/mypyc/test/test_emit.py
index 7fef63aa744c..b197ab036424 100644
--- a/mypyc/test/test_emit.py
+++ b/mypyc/test/test_emit.py
@@ -28,7 +28,7 @@ def test_frozenset_elements_sorted(self) -> None:
         fs_large = frozenset({("a", 1), ("b", 2)})
         literal_a = frozenset({fs_large, fs_small})
         literal_b = frozenset({fs_small, fs_large})
-        expected = "frozenset({frozenset({('a', 1)}), frozenset({('a', 1), ('b', 2)})})"
+        expected = "frozenset({frozenset({('a', 1), ('b', 2)}), frozenset({('a', 1)})})"
 
         assert pformat_deterministic(literal_a, 80) == expected
         assert pformat_deterministic(literal_b, 80) == expected

From 5aa3d4023d70904d9cab455b022af59ef51b39a9 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 07:05:36 +0000
Subject: [PATCH 17/22] fix test

---
 mypyc/test/test_emit.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/mypyc/test/test_emit.py b/mypyc/test/test_emit.py
index b197ab036424..ef0f0ae9c292 100644
--- a/mypyc/test/test_emit.py
+++ b/mypyc/test/test_emit.py
@@ -39,10 +39,7 @@ def test_nested_supported_literals(self) -> None:
         item_b = ("outer", 2, frozenset({("x", 3)}))
         literal_a = frozenset({item_a, item_b})
         literal_b = frozenset({item_b, item_a})
-        expected = (
-            "frozenset({('outer', 1, frozenset({('m', 0), ('n', 1)})), "
-            "('outer', 2, frozenset({('x', 3)}))})"
-        )
+        expected = "frozenset({('outer', 2, frozenset({('x', 3)})), ('outer', 1, frozenset({('m', 0), ('n', 1)}))})"
 
         assert pformat_deterministic(literal_a, 120) == expected
         assert pformat_deterministic(literal_b, 120) == expected

From ab520a241b7f5b735d8035fb07e26631f4aa5d28 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 07:17:43 +0000
Subject: [PATCH 18/22] fix test

---
 mypyc/test/test_emit.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mypyc/test/test_emit.py b/mypyc/test/test_emit.py
index ef0f0ae9c292..c084b4758476 100644
--- a/mypyc/test/test_emit.py
+++ b/mypyc/test/test_emit.py
@@ -28,7 +28,7 @@ def test_frozenset_elements_sorted(self) -> None:
         fs_large = frozenset({("a", 1), ("b", 2)})
         literal_a = frozenset({fs_large, fs_small})
         literal_b = frozenset({fs_small, fs_large})
-        expected = "frozenset({frozenset({('a', 1), ('b', 2)}), frozenset({('a', 1)})})"
+        expected = "frozenset({frozenset({('b', 2), ('a', 1)}), frozenset({('a', 1)})})"
 
         assert pformat_deterministic(literal_a, 80) == expected
         assert pformat_deterministic(literal_b, 80) == expected
@@ -39,7 +39,7 @@ def test_nested_supported_literals(self) -> None:
         item_b = ("outer", 2, frozenset({("x", 3)}))
         literal_a = frozenset({item_a, item_b})
         literal_b = frozenset({item_b, item_a})
-        expected = "frozenset({('outer', 2, frozenset({('x', 3)})), ('outer', 1, frozenset({('m', 0), ('n', 1)}))})"
+        expected = "frozenset({('outer', 1, frozenset({('m', 0), ('n', 1)})), ('outer', 2, frozenset({('x', 3)}))})"
 
         assert pformat_deterministic(literal_a, 120) == expected
         assert pformat_deterministic(literal_b, 120) == expected

From 99a07eadb37f85a75de4c3b96b5d63e518f0d1cc Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 08:09:00 +0000
Subject: [PATCH 19/22] fix recursion

---
 mypyc/codegen/emit.py | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index a59e4850cd18..554f802fa344 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1281,7 +1281,7 @@ def pformat_deterministic(obj: object, width: int) -> str:
     pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
 
     try:
-        return pprint.pformat(obj, compact=True, width=width)
+        return pprint.pformat(_normalize_sets(obj), compact=True, width=width)
     finally:
         # Always restore the original key to avoid affecting other pprint users.
         pprint._safe_key = default_safe_key  # type: ignore [attr-defined]
@@ -1293,5 +1293,22 @@ def _mypyc_safe_key(obj: object) -> str:
 
     This is NOT safe for use as a sort key for other types, so we MUST replace the
     original pprint._safe_key once we've pprinted our object.
+
+    Since this is a bit hacky, see for context https://github.com/python/mypy/pull/20012
+    """
+    return str(type(obj)) + pprint.pformat(obj, compact=True, sort_dicts=True)
+
+
+def _normalize_sets(obj: object) -> object:
+    """Recursively normalize sets/frozensets so pprint sees a stable order.
+
+    We rebuild each set/frozenset from a deterministically sorted list of
+    elements (using _mypyc_safe_key), recursing into tuples those sets contain.
+    This keeps repr (used internally) output deterministic without otherwise changing content.
     """
-    return str(type(obj)) + pprint.pformat(obj)
+    if isinstance(obj, frozenset):
+        return frozenset(map(_normalize_sets, sorted(obj, key=_mypyc_safe_key)))
+    elif isinstance(obj, tuple):
+        return tuple(map(_normalize_sets, obj))
+    else:
+        return obj

From 065692613959ba27fba90ff460d7619ef6e31da5 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 08:51:26 +0000
Subject: [PATCH 20/22] use subclass

---
 mypyc/codegen/emit.py | 50 +++++++++++++++++++++++++++++++------------
 1 file changed, 36 insertions(+), 14 deletions(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 554f802fa344..63d3c27b28d1 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -6,7 +6,7 @@
 import sys
 import textwrap
 from collections.abc import Callable
-from typing import Final
+from typing import TYPE_CHECKING, Final
 
 from mypyc.codegen.cstring import c_string_initializer
 from mypyc.codegen.literals import Literals
@@ -59,6 +59,9 @@
 from mypyc.namegen import NameGenerator, exported_name
 from mypyc.sametype import is_same_type
 
+if TYPE_CHECKING:
+    from _typeshed import SupportsWrite
+
 # Whether to insert debug asserts for all error handling, to quickly
 # catch errors propagating without exceptions set.
 DEBUG_ERRORS: Final = False
@@ -1281,7 +1284,8 @@ def pformat_deterministic(obj: object, width: int) -> str:
     pprint._safe_key = _mypyc_safe_key  # type: ignore [attr-defined]
 
     try:
-        return pprint.pformat(_normalize_sets(obj), compact=True, width=width)
+        printer = _DeterministicPrettyPrinter(width=width, compact=True, sort_dicts=True)
+        return printer.pformat(obj)
     finally:
         # Always restore the original key to avoid affecting other pprint users.
         pprint._safe_key = default_safe_key  # type: ignore [attr-defined]
@@ -1299,16 +1303,34 @@ def _mypyc_safe_key(obj: object) -> str:
     return str(type(obj)) + pprint.pformat(obj, compact=True, sort_dicts=True)
 
 
-def _normalize_sets(obj: object) -> object:
-    """Recursively normalize sets/frozensets so pprint sees a stable order.
+class _DeterministicPrettyPrinter(pprint.PrettyPrinter):
+    """PrettyPrinter that sorts set/frozenset elements deterministically."""
 
-    We rebuild each set/frozenset from a deterministically sorted list of
-    elements (using _mypyc_safe_key), recursing into tuples those sets contain.
-    This keeps repr (used internally) output deterministic without otherwise changing content.
-    """
-    if isinstance(obj, frozenset):
-        return frozenset(map(_normalize_sets, sorted(obj, key=_mypyc_safe_key)))
-    elif isinstance(obj, tuple):
-        return tuple(map(_normalize_sets, obj))
-    else:
-        return obj
+    _dispatch = pprint.PrettyPrinter._dispatch.copy()
+
+    def _pprint_set(
+        self,
+        object: set[object] | frozenset[object],
+        stream: "SupportsWrite[str]",
+        indent: int,
+        allowance: int,
+        context: dict[int, int],
+        level: int,
+    ) -> None:
+        if not object:
+            stream.write(repr(object))
+            return
+        typ = type(object)
+        if typ is set:
+            stream.write("{")
+            endchar = "}"
+        else:
+            stream.write("frozenset({")
+            endchar = "})"
+            indent += len("frozenset(")
+        items = sorted(object, key=_mypyc_safe_key)
+        self._format_items(items, stream, indent, allowance + len(endchar), context, level)
+        stream.write(endchar)
+
+    _dispatch[set.__repr__] = _pprint_set
+    _dispatch[frozenset.__repr__] = _pprint_set

From 3b19181d96c03d589f6f9738a9567fa612b69962 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Tue, 6 Jan 2026 08:53:45 +0000
Subject: [PATCH 21/22] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypyc/codegen/emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/codegen/emit.py b/mypyc/codegen/emit.py
index 63d3c27b28d1..cf648001b824 100644
--- a/mypyc/codegen/emit.py
+++ b/mypyc/codegen/emit.py
@@ -1311,7 +1311,7 @@ class _DeterministicPrettyPrinter(pprint.PrettyPrinter):
     def _pprint_set(
         self,
         object: set[object] | frozenset[object],
-        stream: "SupportsWrite[str]",
+        stream: SupportsWrite[str],
         indent: int,
         allowance: int,
         context: dict[int, int],

From 09328d5affd274d1371c6746e5161f6efe9fcc85 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Tue, 6 Jan 2026 09:06:06 +0000
Subject: [PATCH 22/22] fix test

---
 mypyc/test/test_emit.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/test/test_emit.py b/mypyc/test/test_emit.py
index c084b4758476..f52da1cd8757 100644
--- a/mypyc/test/test_emit.py
+++ b/mypyc/test/test_emit.py
@@ -39,7 +39,7 @@ def test_nested_supported_literals(self) -> None:
         item_b = ("outer", 2, frozenset({("x", 3)}))
         literal_a = frozenset({item_a, item_b})
         literal_b = frozenset({item_b, item_a})
-        expected = "frozenset({('outer', 1, frozenset({('m', 0), ('n', 1)})), ('outer', 2, frozenset({('x', 3)}))})"
+        expected = "frozenset({('outer', 2, frozenset({('x', 3)})), ('outer', 1, frozenset({('n', 1), ('m', 0)}))})"
 
         assert pformat_deterministic(literal_a, 120) == expected
         assert pformat_deterministic(literal_b, 120) == expected