From 280b037ffeb0017035998c5fe6796edc6e273a30 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Fri, 12 Jul 2024 17:22:15 -0700
Subject: [PATCH 1/3] Test on Python 3.13-dev

---
 .github/workflows/ci.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 981f49e0c..c3b7af6d2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13-dev"]
         numpy: [null, "numpy>=1.23,<2.0.0", "numpy>=2.0.0rc1"]
         uncertainties: [null, "uncertainties==3.1.6", "uncertainties>=3.1.6,<4.0.0"]
         extras: [null]
@@ -104,7 +104,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12", "3.13-dev"]
         numpy: [ "numpy>=1.23,<2.0.0" ]
     runs-on: windows-latest
 
@@ -165,7 +165,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12", "3.13-dev"]
         numpy: [null, "numpy>=1.23,<2.0.0" ]
     runs-on: macos-latest
 

From 4b34753960979395b304c0f9a290abfc6132c06f Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Fri, 12 Jul 2024 17:23:21 -0700
Subject: [PATCH 2/3] @dataclass(frozen=True) for Python 3.13 compatibility

---
 pint/errors.py | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/pint/errors.py b/pint/errors.py
index 59d3b4569..f080f529d 100644
--- a/pint/errors.py
+++ b/pint/errors.py
@@ -81,12 +81,12 @@ def def_err(self, msg: str):
         return DefinitionError(self.name, self.__class__, msg)
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class PintError(Exception):
     """Base exception for all Pint errors."""
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class DefinitionError(ValueError, PintError):
     """Raised when a definition is not properly constructed."""
 
@@ -102,7 +102,7 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class DefinitionSyntaxError(ValueError, PintError):
     """Raised when a textual definition has a syntax error."""
 
@@ -115,7 +115,7 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class RedefinitionError(ValueError, PintError):
     """Raised when a unit or prefix is redefined."""
 
@@ -130,7 +130,7 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class UndefinedUnitError(AttributeError, PintError):
     """Raised when the units are not defined in the unit registry."""
 
@@ -150,13 +150,13 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class PintTypeError(TypeError, PintError):
     def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class DimensionalityError(PintTypeError):
     """Raised when trying to convert between incompatible units."""
 
@@ -183,7 +183,7 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class OffsetUnitCalculusError(PintTypeError):
     """Raised on ambiguous operations with offset units."""
 
@@ -208,7 +208,7 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class LogarithmicUnitCalculusError(PintTypeError):
     """Raised on inappropriate operations with logarithmic units."""
 
@@ -233,7 +233,7 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class UnitStrippedWarning(UserWarning, PintError):
     msg: str
 
@@ -241,13 +241,13 @@ def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class UnexpectedScaleInContainer(Exception):
     def __reduce__(self):
         return self.__class__, tuple(getattr(self, f.name) for f in fields(self))
 
 
-@dataclass(frozen=False)
+@dataclass(frozen=True)
 class UndefinedBehavior(UserWarning, PintError):
     msg: str
 

From 01ea9943ed2111e65d34b3bea3d86528fdd8adc4 Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Fri, 12 Jul 2024 17:28:42 -0700
Subject: [PATCH 3/3] Changelog entry

---
 CHANGES | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 5ee199f2c..7211e0224 100644
--- a/CHANGES
+++ b/CHANGES
@@ -9,7 +9,7 @@ Pint Changelog
 - Added ℓ as alternative for liter
 - Fix the default behaviour for pint-convert (cli) for importing uncertainties package (PR #2032, Issue #2016)
 - Support permille units and `‰` symbol (PR #2033, Issue #1963)
-
+- Fixed compatibility with Python 3.13 (Issue #1969)
 
 0.24.1 (2024-06-24)
 -----------------