From 8a5a11a5286625306f99804ff5b8ac88d6b7919c Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 21 Apr 2024 22:45:39 -0400
Subject: [PATCH 01/21] Add '--retag' flag to delocate-fuse command

This adds the ability to "retag" a universal2 fused wheel. When running
delocate-fuse with this flag, it will update the filename and the
dist-info file of the fused wheel to reflect that it is a universal2
wheel.
---
 delocate/cmd/delocate_fuse.py |  8 ++-
 delocate/fuse.py              | 92 ++++++++++++++++++++++++++++++++++-
 2 files changed, 97 insertions(+), 3 deletions(-)

diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index 0ad4e66c..6ce8cf2a 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -26,6 +26,12 @@
     help="Directory to store delocated wheels"
     " (default is to overwrite 1st WHEEL input with 2nd)",
 )
+parser.add_argument(
+    "--retag",
+    action="store_true",
+    help="Retag the fused wheel. This includes updating its filename and"
+    " dist-info (Only works when fusing to make a universal2 wheel)"
+)
 
 
 def main() -> None:  # noqa: D103
@@ -36,7 +42,7 @@ def main() -> None:  # noqa: D103
         out_wheel = wheel1
     else:
         out_wheel = pjoin(abspath(expanduser(args.wheel_dir)), basename(wheel1))
-    fuse_wheels(wheel1, wheel2, out_wheel)
+    fuse_wheels(wheel1, wheel2, out_wheel, retag=args.retag)
 
 
 if __name__ == "__main__":
diff --git a/delocate/fuse.py b/delocate/fuse.py
index 75bf3abf..ee2838d1 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -14,7 +14,7 @@
 
 import os
 import shutil
-from os.path import abspath, exists, relpath, splitext
+from os.path import abspath, basename, dirname, exists, relpath, splitext
 from os.path import join as pjoin
 
 from .tmpdirs import InTemporaryDirectory
@@ -27,7 +27,12 @@
     zip2dir,
 )
 from .wheeltools import rewrite_record
+from .pkginfo import read_pkg_info, write_pkg_info
 
+from packaging.utils import parse_wheel_filename
+
+class RetagWheelError(Exception):
+    """Errors raised when trying to retag a wheel."""
 
 def _copyfile(in_fname, out_fname):
     # Copies files without read / write permission
@@ -38,6 +43,75 @@ def _copyfile(in_fname, out_fname):
         fobj.write(contents)
     os.chmod(out_fname, perms)
 
+def retag_wheel(to_wheel, from_wheel, to_tree):
+    """Update the name and dist-info to reflect a univeral2 wheel.
+
+    Parameters
+    ----------
+    to_wheel : str
+        filename of wheel to fuse into
+    from_wheel : str
+        filename of wheel to fuse from
+    to_tree : str
+        path of tree to fuse into (update into)
+
+    Returns
+    -------
+    retag_name : str
+        The new, retagged name the out wheel should be.
+
+    Raises
+    ------
+    RetagWheelError
+        When the wheels given don't satisfy the requirement that one is x86_64
+        and the other is arm64.
+        When either wheel has more than one tag.
+    """
+    x86_64_wheel = None
+    arm64_wheel = None
+    for wheel in [to_wheel, from_wheel]:
+        if wheel.endswith("x86_64.whl"):
+            x86_64_wheel = wheel
+        elif wheel.endswith("arm64.whl"):
+            arm64_wheel = wheel
+    if x86_64_wheel is None or arm64_wheel is None:
+        raise RetagWheelError("Must have an x86_64 and an arm64 wheel to retag for universal2.")
+
+    name, version, _, x86_64_wheel_tags = parse_wheel_filename(basename(x86_64_wheel))
+    _, _, _, arm64_wheel_tags = parse_wheel_filename(basename(arm64_wheel))
+
+    if len(x86_64_wheel_tags) != 1 or len(arm64_wheel_tags) != 1:
+        err_msg = "Must only have 1 tag in each wheel to retag for universal2."
+        if len(x86_64_wheel_tags) != 1:
+            err_msg += f" The x86_64 wheel has {len(x86_64_wheel_tags)} tags."
+        if len(arm64_wheel_tags) != 1:
+            err_msg += f" The arm64 wheel has {len(arm64_wheel_tags)} tags."
+        raise RetagWheelError(err_msg)
+
+    x86_64_wheel_tag = list(x86_64_wheel_tags)[0]
+    arm64_wheel_tag = list(arm64_wheel_tags)[0]
+    x86_64_wheel_macos_version = x86_64_wheel_tag.platform.split("_")[1:3]
+    arm64_wheel_macos_version = arm64_wheel_tag.platform.split("_")[1:3]
+
+    # Use the x86_64 wheel's platform version when the arm64 wheel's platform
+    # version is 11.0.
+    # For context on why this is done: https://github.com/pypa/wheel/pull/390
+    if arm64_wheel_macos_version == ["11", "0"]:
+        retag_name = basename(x86_64_wheel).removesuffix("x86_64.whl")
+    else:
+        retag_name = basename(arm64_wheel).removesuffix("arm64.whl")
+    retag_name += "universal2.whl"
+
+    normalized_name = name.replace("-", "_")
+    info_path = pjoin(to_tree, f"{normalized_name}-{version}.dist-info", "WHEEL")
+    _, _, _, retag_tags = parse_wheel_filename(retag_name)
+    retag_tag = list(retag_tags)[0]
+    info = read_pkg_info(info_path)
+    del info["Tag"]
+    info["Tag"] = str(retag_tag)
+    write_pkg_info(info_path, info)
+
+    return retag_name
 
 def fuse_trees(to_tree, from_tree, lib_exts=(".so", ".dylib", ".a")):
     """Fuse path `from_tree` into path `to_tree`.
@@ -83,7 +157,7 @@ def fuse_trees(to_tree, from_tree, lib_exts=(".so", ".dylib", ".a")):
                 _copyfile(from_path, to_path)
 
 
-def fuse_wheels(to_wheel, from_wheel, out_wheel):
+def fuse_wheels(to_wheel, from_wheel, out_wheel, retag):
     """Fuse `from_wheel` into `to_wheel`, write to `out_wheel`.
 
     Parameters
@@ -94,13 +168,27 @@ def fuse_wheels(to_wheel, from_wheel, out_wheel):
         filename of wheel to fuse from
     out_wheel : str
         filename of new wheel from fusion of `to_wheel` and `from_wheel`
+    retag : bool
+        update the name and dist-info of the out_wheel to reflect univeral2
+
+    Returns
+    -------
+    out_wheel : str
+        filename of new wheel from fusion of `to_wheel` and `from_wheel` (May be
+        different than what was passed in to the function when `retag` is
+        `True`)
     """
     to_wheel, from_wheel, out_wheel = [
         abspath(w) for w in (to_wheel, from_wheel, out_wheel)
     ]
+
     with InTemporaryDirectory():
         zip2dir(to_wheel, "to_wheel")
         zip2dir(from_wheel, "from_wheel")
         fuse_trees("to_wheel", "from_wheel")
+        if retag:
+            out_wheel_name = retag_wheel(to_wheel, from_wheel, "to_wheel")
+            out_wheel = pjoin(dirname(out_wheel), out_wheel_name)
         rewrite_record("to_wheel")
         dir2zip("to_wheel", out_wheel)
+    return out_wheel

From 80e121c35547baa2c0d970e215e209f6cd3a6758 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 21 Apr 2024 23:11:31 -0400
Subject: [PATCH 02/21] Fix formatting

---
 delocate/cmd/delocate_fuse.py |  2 +-
 delocate/fuse.py              | 27 ++++++++++++++++++---------
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index 6ce8cf2a..bf29058f 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -30,7 +30,7 @@
     "--retag",
     action="store_true",
     help="Retag the fused wheel. This includes updating its filename and"
-    " dist-info (Only works when fusing to make a universal2 wheel)"
+    " dist-info (Only works when fusing to make a universal2 wheel)",
 )
 
 
diff --git a/delocate/fuse.py b/delocate/fuse.py
index ee2838d1..65d72234 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -14,9 +14,13 @@
 
 import os
 import shutil
-from os.path import abspath, basename, dirname, exists, relpath, splitext
+from os.path import abspath, basename, exists, relpath, splitext
+from os.path import dirname as pdirname
 from os.path import join as pjoin
 
+from packaging.utils import parse_wheel_filename
+
+from .pkginfo import read_pkg_info, write_pkg_info
 from .tmpdirs import InTemporaryDirectory
 from .tools import (
     chmod_perms,
@@ -27,13 +31,12 @@
     zip2dir,
 )
 from .wheeltools import rewrite_record
-from .pkginfo import read_pkg_info, write_pkg_info
 
-from packaging.utils import parse_wheel_filename
 
 class RetagWheelError(Exception):
     """Errors raised when trying to retag a wheel."""
 
+
 def _copyfile(in_fname, out_fname):
     # Copies files without read / write permission
     perms = chmod_perms(in_fname)
@@ -43,6 +46,7 @@ def _copyfile(in_fname, out_fname):
         fobj.write(contents)
     os.chmod(out_fname, perms)
 
+
 def retag_wheel(to_wheel, from_wheel, to_tree):
     """Update the name and dist-info to reflect a univeral2 wheel.
 
@@ -75,9 +79,13 @@ def retag_wheel(to_wheel, from_wheel, to_tree):
         elif wheel.endswith("arm64.whl"):
             arm64_wheel = wheel
     if x86_64_wheel is None or arm64_wheel is None:
-        raise RetagWheelError("Must have an x86_64 and an arm64 wheel to retag for universal2.")
+        raise RetagWheelError(
+            "Must have an x86_64 and an arm64 wheel to retag for universal2."
+        )
 
-    name, version, _, x86_64_wheel_tags = parse_wheel_filename(basename(x86_64_wheel))
+    name, version, _, x86_64_wheel_tags = parse_wheel_filename(
+        basename(x86_64_wheel)
+    )
     _, _, _, arm64_wheel_tags = parse_wheel_filename(basename(arm64_wheel))
 
     if len(x86_64_wheel_tags) != 1 or len(arm64_wheel_tags) != 1:
@@ -88,9 +96,7 @@ def retag_wheel(to_wheel, from_wheel, to_tree):
             err_msg += f" The arm64 wheel has {len(arm64_wheel_tags)} tags."
         raise RetagWheelError(err_msg)
 
-    x86_64_wheel_tag = list(x86_64_wheel_tags)[0]
     arm64_wheel_tag = list(arm64_wheel_tags)[0]
-    x86_64_wheel_macos_version = x86_64_wheel_tag.platform.split("_")[1:3]
     arm64_wheel_macos_version = arm64_wheel_tag.platform.split("_")[1:3]
 
     # Use the x86_64 wheel's platform version when the arm64 wheel's platform
@@ -103,7 +109,9 @@ def retag_wheel(to_wheel, from_wheel, to_tree):
     retag_name += "universal2.whl"
 
     normalized_name = name.replace("-", "_")
-    info_path = pjoin(to_tree, f"{normalized_name}-{version}.dist-info", "WHEEL")
+    info_path = pjoin(
+        to_tree, f"{normalized_name}-{version}.dist-info", "WHEEL"
+    )
     _, _, _, retag_tags = parse_wheel_filename(retag_name)
     retag_tag = list(retag_tags)[0]
     info = read_pkg_info(info_path)
@@ -113,6 +121,7 @@ def retag_wheel(to_wheel, from_wheel, to_tree):
 
     return retag_name
 
+
 def fuse_trees(to_tree, from_tree, lib_exts=(".so", ".dylib", ".a")):
     """Fuse path `from_tree` into path `to_tree`.
 
@@ -188,7 +197,7 @@ def fuse_wheels(to_wheel, from_wheel, out_wheel, retag):
         fuse_trees("to_wheel", "from_wheel")
         if retag:
             out_wheel_name = retag_wheel(to_wheel, from_wheel, "to_wheel")
-            out_wheel = pjoin(dirname(out_wheel), out_wheel_name)
+            out_wheel = pjoin(pdirname(out_wheel), out_wheel_name)
         rewrite_record("to_wheel")
         dir2zip("to_wheel", out_wheel)
     return out_wheel

From 72a1635437c6cc8d46a538d13bcb914d65f538c3 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Thu, 25 Apr 2024 21:47:13 -0400
Subject: [PATCH 03/21] Update _update_wheelfile to use pkginfo functions

---
 delocate/delocating.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/delocate/delocating.py b/delocate/delocating.py
index 0678f4af..537dddd7 100644
--- a/delocate/delocating.py
+++ b/delocate/delocating.py
@@ -45,6 +45,7 @@
     tree_libs,
     tree_libs_from_directory,
 )
+from .pkginfo import read_pkg_info, write_pkg_info
 from .tmpdirs import TemporaryDirectory
 from .tools import (
     _is_macho_file,
@@ -867,14 +868,11 @@ def _update_wheelfile(wheel_dir: Path, wheel_name: str) -> None:
     """
     platform_tag_set = parse_wheel_filename(wheel_name)[-1]
     (file_path,) = wheel_dir.glob("*.dist-info/WHEEL")
-    with file_path.open(encoding="utf-8") as f:
-        lines = f.readlines()
-    with file_path.open("w", encoding="utf-8") as f:
-        for line in lines:
-            if line.startswith("Tag:"):
-                f.write(f"Tag: {'.'.join(str(x) for x in platform_tag_set)}\n")
-            else:
-                f.write(line)
+    info = read_pkg_info(file_path)
+    del info["Tag"]
+    for tag in platform_tag_set:
+        info.add_header("Tag", str(tag))
+    write_pkg_info(file_path, info)
 
 
 def delocate_wheel(

From 13489f4445d2707ea7feb630542426328ad2a0dc Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Thu, 25 Apr 2024 21:49:48 -0400
Subject: [PATCH 04/21] Detect if a wheel's name should use universal2

This updates '_get_archs_and_version_from_wheel_name' to check if both
arm64 and x86_64 platform tags are in the wheel's filename. If they are
both present, it changes the returned arch to be universal2 with the
appropriate version.
---
 delocate/delocating.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/delocate/delocating.py b/delocate/delocating.py
index 537dddd7..39657fdc 100644
--- a/delocate/delocating.py
+++ b/delocate/delocating.py
@@ -654,6 +654,14 @@ def _get_archs_and_version_from_wheel_name(
             raise ValueError(f"Invalid platform tag: {platform_tag.platform}")
         major, minor, arch = match.groups()
         platform_requirements[arch] = Version(f"{major}.{minor}")
+    # If we have a wheel name with arm64 and x86_64 we have to convert that to
+    # universal2
+    if set(platform_requirements.keys()) == set(("arm64", "x86_64")):
+        version = platform_requirements["arm64"]
+        if version == Version("11.0"):
+            version = platform_requirements["x86_64"]
+        platform_requirements = {"universal2": version}
+
     return platform_requirements
 
 

From e0ec141947e57d55a99f5921c1fb0cdb839f3d13 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Thu, 25 Apr 2024 21:54:23 -0400
Subject: [PATCH 05/21] Update retagging to use functions from delocating

This is now much simpler and more generalized. It first updates the name
to contain platform tags from both from_wheel and to_wheel. Next it
calls '_check_and_update_wheel_name' which fixes any issues with the
name AND will convert it to universal2 if necessary. And finally, it
calls '_update_wheelfile' to update the info in the WHEEL file to match
the new name.
---
 delocate/fuse.py | 73 ++++++++++--------------------------------------
 1 file changed, 15 insertions(+), 58 deletions(-)

diff --git a/delocate/fuse.py b/delocate/fuse.py
index 65d72234..fe4c150a 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -17,10 +17,11 @@
 from os.path import abspath, basename, exists, relpath, splitext
 from os.path import dirname as pdirname
 from os.path import join as pjoin
+from pathlib import Path
 
 from packaging.utils import parse_wheel_filename
 
-from .pkginfo import read_pkg_info, write_pkg_info
+from .delocating import _check_and_update_wheel_name, _update_wheelfile
 from .tmpdirs import InTemporaryDirectory
 from .tools import (
     chmod_perms,
@@ -33,10 +34,6 @@
 from .wheeltools import rewrite_record
 
 
-class RetagWheelError(Exception):
-    """Errors raised when trying to retag a wheel."""
-
-
 def _copyfile(in_fname, out_fname):
     # Copies files without read / write permission
     perms = chmod_perms(in_fname)
@@ -63,61 +60,21 @@ def retag_wheel(to_wheel, from_wheel, to_tree):
     -------
     retag_name : str
         The new, retagged name the out wheel should be.
-
-    Raises
-    ------
-    RetagWheelError
-        When the wheels given don't satisfy the requirement that one is x86_64
-        and the other is arm64.
-        When either wheel has more than one tag.
     """
-    x86_64_wheel = None
-    arm64_wheel = None
-    for wheel in [to_wheel, from_wheel]:
-        if wheel.endswith("x86_64.whl"):
-            x86_64_wheel = wheel
-        elif wheel.endswith("arm64.whl"):
-            arm64_wheel = wheel
-    if x86_64_wheel is None or arm64_wheel is None:
-        raise RetagWheelError(
-            "Must have an x86_64 and an arm64 wheel to retag for universal2."
-        )
-
-    name, version, _, x86_64_wheel_tags = parse_wheel_filename(
-        basename(x86_64_wheel)
+    # Add from_wheel platform tags onto to_wheel filename, but make sure to not
+    # add a tag if it is already there
+    from_wheel_tags = parse_wheel_filename(basename(from_wheel))[-1]
+    to_wheel_tags = parse_wheel_filename(basename(to_wheel))[-1]
+    add_platform_tags = (
+        f".{tag.platform}" for tag in from_wheel_tags - to_wheel_tags
     )
-    _, _, _, arm64_wheel_tags = parse_wheel_filename(basename(arm64_wheel))
-
-    if len(x86_64_wheel_tags) != 1 or len(arm64_wheel_tags) != 1:
-        err_msg = "Must only have 1 tag in each wheel to retag for universal2."
-        if len(x86_64_wheel_tags) != 1:
-            err_msg += f" The x86_64 wheel has {len(x86_64_wheel_tags)} tags."
-        if len(arm64_wheel_tags) != 1:
-            err_msg += f" The arm64 wheel has {len(arm64_wheel_tags)} tags."
-        raise RetagWheelError(err_msg)
-
-    arm64_wheel_tag = list(arm64_wheel_tags)[0]
-    arm64_wheel_macos_version = arm64_wheel_tag.platform.split("_")[1:3]
-
-    # Use the x86_64 wheel's platform version when the arm64 wheel's platform
-    # version is 11.0.
-    # For context on why this is done: https://github.com/pypa/wheel/pull/390
-    if arm64_wheel_macos_version == ["11", "0"]:
-        retag_name = basename(x86_64_wheel).removesuffix("x86_64.whl")
-    else:
-        retag_name = basename(arm64_wheel).removesuffix("arm64.whl")
-    retag_name += "universal2.whl"
-
-    normalized_name = name.replace("-", "_")
-    info_path = pjoin(
-        to_tree, f"{normalized_name}-{version}.dist-info", "WHEEL"
-    )
-    _, _, _, retag_tags = parse_wheel_filename(retag_name)
-    retag_tag = list(retag_tags)[0]
-    info = read_pkg_info(info_path)
-    del info["Tag"]
-    info["Tag"] = str(retag_tag)
-    write_pkg_info(info_path, info)
+    retag_name = Path(to_wheel).stem + "".join(add_platform_tags) + ".whl"
+
+    retag_name = _check_and_update_wheel_name(
+        Path(retag_name), to_tree, None
+    ).name
+
+    _update_wheelfile(Path(to_tree), retag_name)
 
     return retag_name
 

From 270302740ec86e92f1aded5b91a1b922fc179c6c Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sat, 27 Apr 2024 20:21:57 -0400
Subject: [PATCH 06/21] Simplify set comparison syntax

---
 delocate/delocating.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/delocate/delocating.py b/delocate/delocating.py
index 39657fdc..6e540bac 100644
--- a/delocate/delocating.py
+++ b/delocate/delocating.py
@@ -656,7 +656,7 @@ def _get_archs_and_version_from_wheel_name(
         platform_requirements[arch] = Version(f"{major}.{minor}")
     # If we have a wheel name with arm64 and x86_64 we have to convert that to
     # universal2
-    if set(platform_requirements.keys()) == set(("arm64", "x86_64")):
+    if platform_requirements.keys() == {"arm64", "x86_64"}:
         version = platform_requirements["arm64"]
         if version == Version("11.0"):
             version = platform_requirements["x86_64"]

From f31e82c0b6020785d15e8ff604780ae6345e8f60 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 10:56:43 -0400
Subject: [PATCH 07/21] Make fuse retagging the default behavior

This also updates the fuse function to support pathlib paths and updates
the retagging function to use pathlib paths.
---
 delocate/cmd/delocate_fuse.py | 26 ++++++-------
 delocate/fuse.py              | 73 ++++++++++++++++++++---------------
 2 files changed, 52 insertions(+), 47 deletions(-)

diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index bf29058f..e19fa7cc 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -1,15 +1,14 @@
 #!/usr/bin/env python3
 """Fuse two (probably delocated) wheels.
 
-Overwrites the first wheel in-place by default.
+Writes to a new wheel with an automatically determined name by default.
 """
 
 # vim: ft=python
 from __future__ import absolute_import, division, print_function
 
 from argparse import ArgumentParser
-from os.path import abspath, basename, expanduser
-from os.path import join as pjoin
+from pathlib import Path
 
 from delocate.cmd.common import common_parser, verbosity_config
 from delocate.fuse import fuse_wheels
@@ -24,25 +23,22 @@
     action="store",
     type=str,
     help="Directory to store delocated wheels"
-    " (default is to overwrite 1st WHEEL input with 2nd)",
-)
-parser.add_argument(
-    "--retag",
-    action="store_true",
-    help="Retag the fused wheel. This includes updating its filename and"
-    " dist-info (Only works when fusing to make a universal2 wheel)",
+    " (default is to store in the same directory as the 1st WHEEL with an"
+    " automatically determined name).",
 )
 
 
 def main() -> None:  # noqa: D103
     args = parser.parse_args()
     verbosity_config(args)
-    wheel1, wheel2 = [abspath(expanduser(wheel)) for wheel in args.wheels]
-    if args.wheel_dir is None:
-        out_wheel = wheel1
+    wheel1, wheel2 = [Path(wheel).resolve() for wheel in args.wheels]
+    if args.wheel_dir is not None:
+        out_wheel = Path(args.wheel_dir).resolve()
+        if not out_wheel.exists():
+            out_wheel.mkdir(parents=True)
     else:
-        out_wheel = pjoin(abspath(expanduser(args.wheel_dir)), basename(wheel1))
-    fuse_wheels(wheel1, wheel2, out_wheel, retag=args.retag)
+        out_wheel = None
+    fuse_wheels(wheel1, wheel2, out_wheel)
 
 
 if __name__ == "__main__":
diff --git a/delocate/fuse.py b/delocate/fuse.py
index fe4c150a..ed151df8 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -14,8 +14,8 @@
 
 import os
 import shutil
-from os.path import abspath, basename, exists, relpath, splitext
-from os.path import dirname as pdirname
+from os import PathLike
+from os.path import exists, relpath, splitext
 from os.path import join as pjoin
 from pathlib import Path
 
@@ -44,37 +44,38 @@ def _copyfile(in_fname, out_fname):
     os.chmod(out_fname, perms)
 
 
-def retag_wheel(to_wheel, from_wheel, to_tree):
+def _retag_wheel(to_wheel: Path, from_wheel: Path, to_tree: Path) -> str:
     """Update the name and dist-info to reflect a univeral2 wheel.
 
     Parameters
     ----------
-    to_wheel : str
-        filename of wheel to fuse into
-    from_wheel : str
-        filename of wheel to fuse from
-    to_tree : str
-        path of tree to fuse into (update into)
+    to_wheel : Path
+        The path of the wheel to fuse into.
+    from_wheel : Path
+        The path of the wheel to fuse from.
+    to_tree : Path
+        The path of the directory tree to fuse into (update into).
 
     Returns
     -------
     retag_name : str
         The new, retagged name the out wheel should be.
     """
+    to_tree = to_tree.resolve()
     # Add from_wheel platform tags onto to_wheel filename, but make sure to not
     # add a tag if it is already there
-    from_wheel_tags = parse_wheel_filename(basename(from_wheel))[-1]
-    to_wheel_tags = parse_wheel_filename(basename(to_wheel))[-1]
+    from_wheel_tags = parse_wheel_filename(from_wheel.name)[-1]
+    to_wheel_tags = parse_wheel_filename(to_wheel.name)[-1]
     add_platform_tags = (
         f".{tag.platform}" for tag in from_wheel_tags - to_wheel_tags
     )
-    retag_name = Path(to_wheel).stem + "".join(add_platform_tags) + ".whl"
+    retag_name = to_wheel.stem + "".join(add_platform_tags) + ".whl"
 
     retag_name = _check_and_update_wheel_name(
         Path(retag_name), to_tree, None
     ).name
 
-    _update_wheelfile(Path(to_tree), retag_name)
+    _update_wheelfile(to_tree, retag_name)
 
     return retag_name
 
@@ -123,38 +124,46 @@ def fuse_trees(to_tree, from_tree, lib_exts=(".so", ".dylib", ".a")):
                 _copyfile(from_path, to_path)
 
 
-def fuse_wheels(to_wheel, from_wheel, out_wheel, retag):
+def fuse_wheels(
+    to_wheel: str | PathLike,
+    from_wheel: str | PathLike,
+    out_wheel: str | PathLike | None = None,
+) -> Path:
     """Fuse `from_wheel` into `to_wheel`, write to `out_wheel`.
 
     Parameters
     ----------
-    to_wheel : str
-        filename of wheel to fuse into
-    from_wheel : str
-        filename of wheel to fuse from
-    out_wheel : str
-        filename of new wheel from fusion of `to_wheel` and `from_wheel`
-    retag : bool
-        update the name and dist-info of the out_wheel to reflect univeral2
+    to_wheel : str or Path-like
+        The path of the wheel to fuse into.
+    from_wheel : str or Path-like
+        The path of the wheel to fuse from.
+    out_wheel : str or Path-like, optional
+        The path of the new wheel from fusion of `to_wheel` and `from_wheel`. If
+        a full path is given, (including the filename) it will be used as is. If
+        a directory is given, the fused wheel will be stored in the directory,
+        with the name of the wheel automatically determined. If no path is
+        given, the fused wheel will be stored in the same directory as
+        `to_wheel`, with the name of the wheel automatically determined.
 
     Returns
     -------
-    out_wheel : str
-        filename of new wheel from fusion of `to_wheel` and `from_wheel` (May be
-        different than what was passed in to the function when `retag` is
-        `True`)
+    out_wheel : Path
+        The path of the new wheel from fusion of `to_wheel` and `from_wheel`.
     """
-    to_wheel, from_wheel, out_wheel = [
-        abspath(w) for w in (to_wheel, from_wheel, out_wheel)
-    ]
+    to_wheel, from_wheel = [Path(w).resolve() for w in (to_wheel, from_wheel)]
+    out_wheel = (
+        to_wheel.parent if out_wheel is None else Path(out_wheel).resolve()
+    )
 
     with InTemporaryDirectory():
         zip2dir(to_wheel, "to_wheel")
         zip2dir(from_wheel, "from_wheel")
         fuse_trees("to_wheel", "from_wheel")
-        if retag:
-            out_wheel_name = retag_wheel(to_wheel, from_wheel, "to_wheel")
-            out_wheel = pjoin(pdirname(out_wheel), out_wheel_name)
+        if out_wheel.is_dir():
+            out_wheel_name = _retag_wheel(
+                to_wheel, from_wheel, Path("to_wheel")
+            )
+            out_wheel = out_wheel / out_wheel_name
         rewrite_record("to_wheel")
         dir2zip("to_wheel", out_wheel)
     return out_wheel

From f8e8a1ec6e182071a2797429e230779707a9ee0b Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 16:06:02 -0400
Subject: [PATCH 08/21] Resolve wheel path's strictly & fix mypy errors

---
 delocate/cmd/delocate_fuse.py | 4 ++--
 delocate/fuse.py              | 6 +++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index e19fa7cc..852fa127 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -5,7 +5,7 @@
 """
 
 # vim: ft=python
-from __future__ import absolute_import, division, print_function
+from __future__ import annotations
 
 from argparse import ArgumentParser
 from pathlib import Path
@@ -31,7 +31,7 @@
 def main() -> None:  # noqa: D103
     args = parser.parse_args()
     verbosity_config(args)
-    wheel1, wheel2 = [Path(wheel).resolve() for wheel in args.wheels]
+    wheel1, wheel2 = [Path(wheel).resolve(strict=True) for wheel in args.wheels]
     if args.wheel_dir is not None:
         out_wheel = Path(args.wheel_dir).resolve()
         if not out_wheel.exists():
diff --git a/delocate/fuse.py b/delocate/fuse.py
index ed151df8..2c09899b 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -12,6 +12,8 @@
 libraries.
 """
 
+from __future__ import annotations
+
 import os
 import shutil
 from os import PathLike
@@ -150,7 +152,9 @@ def fuse_wheels(
     out_wheel : Path
         The path of the new wheel from fusion of `to_wheel` and `from_wheel`.
     """
-    to_wheel, from_wheel = [Path(w).resolve() for w in (to_wheel, from_wheel)]
+    to_wheel, from_wheel = [
+        Path(w).resolve(strict=True) for w in (to_wheel, from_wheel)
+    ]
     out_wheel = (
         to_wheel.parent if out_wheel is None else Path(out_wheel).resolve()
     )

From 9790cb39510c14ad89108846ceeb0fa576dc0f0c Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 16:13:29 -0400
Subject: [PATCH 09/21] Update changelog to include automatic retagging PR

---
 Changelog.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Changelog.md b/Changelog.md
index d5631a0f..b2733526 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -14,6 +14,9 @@ rules on making a good Changelog.
 
 - Improved error message for when a MacOS target version is not met.
   [#211](https://github.com/matthew-brett/delocate/issues/211)
+- Retag wheels automatically when fusing to ensure the wheel name and WHEEL
+  file tag data is accurate.
+  [#215](https://github.com/matthew-brett/delocate/pull/215)
 
 ## [0.11.0] - 2024-03-22
 

From 7db982d5afe101e37bcba5bfdbb41f4c8f6c9344 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 20:26:54 -0400
Subject: [PATCH 10/21] Update Changelog & README for retagging

---
 Changelog.md |  4 ++--
 README.rst   | 12 +-----------
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/Changelog.md b/Changelog.md
index b2733526..0ea8bf18 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -14,8 +14,8 @@ rules on making a good Changelog.
 
 - Improved error message for when a MacOS target version is not met.
   [#211](https://github.com/matthew-brett/delocate/issues/211)
-- Retag wheels automatically when fusing to ensure the wheel name and WHEEL
-  file tag data is accurate.
+- `delocate-fuse` will now output to a new wheel with updated tags instead of
+  replacing the first wheel given.
   [#215](https://github.com/matthew-brett/delocate/pull/215)
 
 ## [0.11.0] - 2024-03-22
diff --git a/README.rst b/README.rst
index f3ab0ff3..0180affb 100644
--- a/README.rst
+++ b/README.rst
@@ -197,21 +197,11 @@ subdirectory with::
 
 The output wheel in that case would be:
 
-* ``tmp/scipy-1.9.3-cp311-cp311-macosx_12_0_arm64.whl``
-
-Note that we specified an output directory above with the ``-w`` flag.  If we
-had not done that, then we overwrite the first wheel with the fused wheel.  And
-note that the wheel written into the ``tmp`` subdirectory has the same name as
-the first-specified wheel.
+* ``tmp/scipy-1.9.3-cp311-cp311-macosx_12_0_universal2.whl``
 
 In the new wheel, you will find, using ``lipo -archs`` - that all binaries with
 the same name in each wheel are now universal (``x86_64`` and ``arm64``).
 
-To be useful, you should rename the output wheel to reflect the fact that it is
-now a universal wheel - in this case to:
-
-* ``tmp/scipy-1.9.3-cp311-cp311-macosx_12_0_universal2.whl``
-
 Troubleshooting
 ===============
 

From 24612595431da8dd4cafc6a54889986fc8a0f391 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 20:28:08 -0400
Subject: [PATCH 11/21] Update fuse_trees temp context

This also required some typing changes to functions called by
fused_trees.
---
 delocate/fuse.py       | 36 +++++++++++++++++++++---------------
 delocate/wheeltools.py |  5 +++--
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/delocate/fuse.py b/delocate/fuse.py
index 2c09899b..636b60e4 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -16,6 +16,7 @@
 
 import os
 import shutil
+import tempfile
 from os import PathLike
 from os.path import exists, relpath, splitext
 from os.path import join as pjoin
@@ -24,7 +25,6 @@
 from packaging.utils import parse_wheel_filename
 
 from .delocating import _check_and_update_wheel_name, _update_wheelfile
-from .tmpdirs import InTemporaryDirectory
 from .tools import (
     chmod_perms,
     cmp_contents,
@@ -82,7 +82,11 @@ def _retag_wheel(to_wheel: Path, from_wheel: Path, to_tree: Path) -> str:
     return retag_name
 
 
-def fuse_trees(to_tree, from_tree, lib_exts=(".so", ".dylib", ".a")):
+def fuse_trees(
+    to_tree: str | PathLike,
+    from_tree: str | PathLike,
+    lib_exts=(".so", ".dylib", ".a"),
+):
     """Fuse path `from_tree` into path `to_tree`.
 
     For each file in `from_tree` - check for library file extension (in
@@ -93,14 +97,14 @@ def fuse_trees(to_tree, from_tree, lib_exts=(".so", ".dylib", ".a")):
 
     Parameters
     ----------
-    to_tree : str
+    to_tree : str or Path-like
         path of tree to fuse into (update into)
-    from_tree : str
+    from_tree : str or Path-like
         path of tree to fuse from (update from)
     lib_exts : sequence, optional
         filename extensions for libraries
     """
-    for from_dirpath, dirnames, filenames in os.walk(from_tree):
+    for from_dirpath, dirnames, filenames in os.walk(str(from_tree)):
         to_dirpath = pjoin(to_tree, relpath(from_dirpath, from_tree))
         # Copy any missing directories in to_path
         for dirname in tuple(dirnames):
@@ -151,6 +155,9 @@ def fuse_wheels(
     -------
     out_wheel : Path
         The path of the new wheel from fusion of `to_wheel` and `from_wheel`.
+
+    .. versionchanged:: 0.12
+        `out_wheel` can now take a directory or None.
     """
     to_wheel, from_wheel = [
         Path(w).resolve(strict=True) for w in (to_wheel, from_wheel)
@@ -158,16 +165,15 @@ def fuse_wheels(
     out_wheel = (
         to_wheel.parent if out_wheel is None else Path(out_wheel).resolve()
     )
-
-    with InTemporaryDirectory():
-        zip2dir(to_wheel, "to_wheel")
-        zip2dir(from_wheel, "from_wheel")
-        fuse_trees("to_wheel", "from_wheel")
+    with tempfile.TemporaryDirectory() as temp_dir:
+        to_wheel_dir = Path(temp_dir, "to_wheel")
+        from_wheel_dir = Path(temp_dir, "from_wheel")
+        zip2dir(to_wheel, to_wheel_dir)
+        zip2dir(from_wheel, from_wheel_dir)
+        fuse_trees(to_wheel_dir, from_wheel_dir)
         if out_wheel.is_dir():
-            out_wheel_name = _retag_wheel(
-                to_wheel, from_wheel, Path("to_wheel")
-            )
+            out_wheel_name = _retag_wheel(to_wheel, from_wheel, to_wheel_dir)
             out_wheel = out_wheel / out_wheel_name
-        rewrite_record("to_wheel")
-        dir2zip("to_wheel", out_wheel)
+        rewrite_record(to_wheel_dir)
+        dir2zip(to_wheel_dir, out_wheel)
     return out_wheel
diff --git a/delocate/wheeltools.py b/delocate/wheeltools.py
index e749301a..c80bba0b 100644
--- a/delocate/wheeltools.py
+++ b/delocate/wheeltools.py
@@ -10,6 +10,7 @@
 import os
 import sys
 from itertools import product
+from os import PathLike
 from os.path import abspath, basename, dirname, exists, relpath, splitext
 from os.path import join as pjoin
 from os.path import sep as psep
@@ -34,7 +35,7 @@ def _open_for_csv(name, mode):
     return open_rw(name, mode, newline="", encoding="utf-8")
 
 
-def rewrite_record(bdist_dir: str) -> None:
+def rewrite_record(bdist_dir: str | PathLike) -> None:
     """Rewrite RECORD file with hashes for all files in `wheel_sdir`.
 
     Copied from :method:`wheel.bdist_wheel.bdist_wheel.write_record`.
@@ -43,7 +44,7 @@ def rewrite_record(bdist_dir: str) -> None:
 
     Parameters
     ----------
-    bdist_dir : str
+    bdist_dir : str or Path-like
         Path of unpacked wheel file
     """
     info_dirs = glob.glob(pjoin(bdist_dir, "*.dist-info"))

From 9adf625bec73b4b7a1f7230f8d32a3fd0a48e672 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 21:36:19 -0400
Subject: [PATCH 12/21] Update fuse_wheels test

---
 delocate/tests/test_scripts.py | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/delocate/tests/test_scripts.py b/delocate/tests/test_scripts.py
index 75d3ba22..5553b623 100644
--- a/delocate/tests/test_scripts.py
+++ b/delocate/tests/test_scripts.py
@@ -402,22 +402,23 @@ def _fix_break_fix(arch: Text) -> None:
 def test_fuse_wheels(script_runner: ScriptRunner) -> None:
     # Some tests for wheel fusing
     with InTemporaryDirectory():
+        # Wheels need proper wheel filename for delocate-fuse
+        to_wheel = "to_" + basename(PLAT_WHEEL)
+        from_wheel = "from_" + basename(PLAT_WHEEL)
         zip2dir(PLAT_WHEEL, "to_wheel")
         zip2dir(PLAT_WHEEL, "from_wheel")
-        dir2zip("to_wheel", "to_wheel.whl")
-        dir2zip("from_wheel", "from_wheel.whl")
-        script_runner.run(
-            ["delocate-fuse", "to_wheel.whl", "from_wheel.whl"], check=True
-        )
-        zip2dir("to_wheel.whl", "to_wheel_fused")
+        dir2zip("to_wheel", to_wheel)
+        dir2zip("from_wheel", from_wheel)
+        script_runner.run(["delocate-fuse", to_wheel, from_wheel], check=True)
+        zip2dir(to_wheel, "to_wheel_fused")
         assert_same_tree("to_wheel_fused", "from_wheel")
         # Test output argument
         os.mkdir("wheels")
         script_runner.run(
-            ["delocate-fuse", "to_wheel.whl", "from_wheel.whl", "-w", "wheels"],
+            ["delocate-fuse", to_wheel, from_wheel, "-w", "wheels"],
             check=True,
         )
-        zip2dir(pjoin("wheels", "to_wheel.whl"), "to_wheel_refused")
+        zip2dir(pjoin("wheels", to_wheel), "to_wheel_refused")
         assert_same_tree("to_wheel_refused", "from_wheel")
 
 

From ba78f01027a5c89eec7febf571feba27d72652dd Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Sun, 28 Apr 2024 22:46:36 -0400
Subject: [PATCH 13/21] Fix style/typing

---
 delocate/fuse.py       | 7 +++----
 delocate/wheeltools.py | 2 ++
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/delocate/fuse.py b/delocate/fuse.py
index 636b60e4..2ce3ed74 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -104,7 +104,7 @@ def fuse_trees(
     lib_exts : sequence, optional
         filename extensions for libraries
     """
-    for from_dirpath, dirnames, filenames in os.walk(str(from_tree)):
+    for from_dirpath, dirnames, filenames in os.walk(from_tree):
         to_dirpath = pjoin(to_tree, relpath(from_dirpath, from_tree))
         # Copy any missing directories in to_path
         for dirname in tuple(dirnames):
@@ -159,9 +159,8 @@ def fuse_wheels(
     .. versionchanged:: 0.12
         `out_wheel` can now take a directory or None.
     """
-    to_wheel, from_wheel = [
-        Path(w).resolve(strict=True) for w in (to_wheel, from_wheel)
-    ]
+    to_wheel = Path(to_wheel).resolve(strict=True)
+    from_wheel = Path(from_wheel).resolve(strict=True)
     out_wheel = (
         to_wheel.parent if out_wheel is None else Path(out_wheel).resolve()
     )
diff --git a/delocate/wheeltools.py b/delocate/wheeltools.py
index c80bba0b..82fd9a46 100644
--- a/delocate/wheeltools.py
+++ b/delocate/wheeltools.py
@@ -3,6 +3,8 @@
 Tools that aren't specific to delocation.
 """
 
+from __future__ import annotations
+
 import base64
 import csv
 import glob

From f90341cc5d62b6e522d9a250cbf736994c0a80f4 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Mon, 29 Apr 2024 00:26:12 -0400
Subject: [PATCH 14/21] Pacify mypy

---
 delocate/fuse.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/delocate/fuse.py b/delocate/fuse.py
index 2ce3ed74..99186d76 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -104,7 +104,7 @@ def fuse_trees(
     lib_exts : sequence, optional
         filename extensions for libraries
     """
-    for from_dirpath, dirnames, filenames in os.walk(from_tree):
+    for from_dirpath, dirnames, filenames in os.walk(Path(from_tree)):
         to_dirpath = pjoin(to_tree, relpath(from_dirpath, from_tree))
         # Copy any missing directories in to_path
         for dirname in tuple(dirnames):

From 10949cb9a298aa00be3197a3a1306ee3315c04ba Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Mon, 29 Apr 2024 11:18:29 -0400
Subject: [PATCH 15/21] Address coverage issues

---
 delocate/cmd/delocate_fuse.py     | 3 +--
 delocate/tests/test_delocating.py | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index 852fa127..bd36dd03 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -34,8 +34,7 @@ def main() -> None:  # noqa: D103
     wheel1, wheel2 = [Path(wheel).resolve(strict=True) for wheel in args.wheels]
     if args.wheel_dir is not None:
         out_wheel = Path(args.wheel_dir).resolve()
-        if not out_wheel.exists():
-            out_wheel.mkdir(parents=True)
+        out_wheel.mkdir(parents=True, exist_ok=True)
     else:
         out_wheel = None
     fuse_wheels(wheel1, wheel2, out_wheel)
diff --git a/delocate/tests/test_delocating.py b/delocate/tests/test_delocating.py
index 3ce23cb4..23cf0892 100644
--- a/delocate/tests/test_delocating.py
+++ b/delocate/tests/test_delocating.py
@@ -722,6 +722,9 @@ def test_get_archs_and_version_from_wheel_name() -> None:
     ) == {
         "arm64": Version("12.0"),
     }
+    assert _get_archs_and_version_from_wheel_name(
+        "foo-1.0-py310-abi3-macosx_10_9_x86_64.macosx_11_0_arm64.whl"
+    )
     with pytest.raises(InvalidWheelFilename, match="Invalid wheel filename"):
         _get_archs_and_version_from_wheel_name("foo.whl")
 

From 80b0d8b1d343f9012de2659c7ce609c160749b98 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Mon, 29 Apr 2024 14:26:35 -0400
Subject: [PATCH 16/21] Fix new delocating test

---
 delocate/tests/test_delocating.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/delocate/tests/test_delocating.py b/delocate/tests/test_delocating.py
index 23cf0892..004193a7 100644
--- a/delocate/tests/test_delocating.py
+++ b/delocate/tests/test_delocating.py
@@ -724,7 +724,9 @@ def test_get_archs_and_version_from_wheel_name() -> None:
     }
     assert _get_archs_and_version_from_wheel_name(
         "foo-1.0-py310-abi3-macosx_10_9_x86_64.macosx_11_0_arm64.whl"
-    )
+    ) == {
+        "universal2": Version("10.9"),
+    }
     with pytest.raises(InvalidWheelFilename, match="Invalid wheel filename"):
         _get_archs_and_version_from_wheel_name("foo.whl")
 

From 160ba3d64b615e21a59669485f9fa5c06a280976 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Wed, 1 May 2024 21:42:12 -0400
Subject: [PATCH 17/21] Add another test for universal2 wheel version

Depending on the version of each wheel being fused, the universal2
wheel's version can be either the x86_64 or the arm64 wheel's version.
The first test for this is testing the scenario where the x86_64 wheel's
version should be used. This new test is tesing the scenario where the
arm64 wheel's version should be used.
---
 delocate/tests/test_delocating.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/delocate/tests/test_delocating.py b/delocate/tests/test_delocating.py
index 004193a7..2ea0f3ee 100644
--- a/delocate/tests/test_delocating.py
+++ b/delocate/tests/test_delocating.py
@@ -727,6 +727,11 @@ def test_get_archs_and_version_from_wheel_name() -> None:
     ) == {
         "universal2": Version("10.9"),
     }
+    assert _get_archs_and_version_from_wheel_name(
+        "foo-1.0-py310-abi3-macosx_10_9_x86_64.macosx_12_0_arm64.whl"
+    ) == {
+        "universal2": Version("12.0"),
+    }
     with pytest.raises(InvalidWheelFilename, match="Invalid wheel filename"):
         _get_archs_and_version_from_wheel_name("foo.whl")
 

From f1716b601e8dc7e88a8ff6fc2edfb0ce8c68dfd4 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Wed, 1 May 2024 21:55:49 -0400
Subject: [PATCH 18/21] Move delocate-fuse functionality to delocate-merge

This moves the old 'delocate-fuse' functionality into the new
'delocate-merge' command. Running 'delocate-fuse' will now print a
message notifying the user of this change and then exit with an exit
code of 1. This also updates relevant tests, the changelog, and the
README.
---
 Changelog.md                   |  7 ++++--
 README.rst                     | 18 +++++++++++---
 delocate/cmd/delocate_fuse.py  | 42 ++++++++++----------------------
 delocate/cmd/delocate_merge.py | 44 ++++++++++++++++++++++++++++++++++
 delocate/tests/test_scripts.py | 12 +++++++---
 pyproject.toml                 |  1 +
 6 files changed, 86 insertions(+), 38 deletions(-)
 create mode 100755 delocate/cmd/delocate_merge.py

diff --git a/Changelog.md b/Changelog.md
index 0ea8bf18..a9b4644a 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -14,8 +14,11 @@ rules on making a good Changelog.
 
 - Improved error message for when a MacOS target version is not met.
   [#211](https://github.com/matthew-brett/delocate/issues/211)
-- `delocate-fuse` will now output to a new wheel with updated tags instead of
-  replacing the first wheel given.
+- `delocate-fuse` is no longer available and will throw an error when invoked.
+  To fuse two wheels together use `delocate-merge`. `delocate-merge` does not
+  overwrite the first wheel. It creates a new wheel with an automatically
+  determined name. If the old behavior is needed (not recommended), pin the
+  version to `delocate==0.11.0`.
   [#215](https://github.com/matthew-brett/delocate/pull/215)
 
 ## [0.11.0] - 2024-03-22
diff --git a/README.rst b/README.rst
index 0180affb..711c358f 100644
--- a/README.rst
+++ b/README.rst
@@ -183,17 +183,17 @@ One solution to this problem is to do an entire ``arm64`` wheel build, and then
 an entire ``x86_64`` wheel build, and *fuse* the two wheels into a universal
 wheel.
 
-That is what the ``delocate-fuse`` command does.
+That is what the ``delocate-merge`` command does.
 
 Let's say you have built an ARM and Intel wheel, called, respectively:
 
 * ``scipy-1.9.3-cp311-cp311-macosx_12_0_arm64.whl``
 * ``scipy-1.9.3-cp311-cp311-macosx_10_9_x86_64.whl``
 
-Then you could create a new fused (``universal2``) wheel in the `tmp`
+Then you could create a new fused (``universal2``) wheel in the ``tmp``
 subdirectory with::
 
-    delocate-fuse scipy-1.9.3-cp311-cp311-macosx_12_0_arm64.whl scipy-1.9.3-cp311-cp311-macosx_10_9_x86_64.whl -w tmp
+    delocate-merge scipy-1.9.3-cp311-cp311-macosx_12_0_arm64.whl scipy-1.9.3-cp311-cp311-macosx_10_9_x86_64.whl -w tmp
 
 The output wheel in that case would be:
 
@@ -202,6 +202,18 @@ The output wheel in that case would be:
 In the new wheel, you will find, using ``lipo -archs`` - that all binaries with
 the same name in each wheel are now universal (``x86_64`` and ``arm64``).
 
+    `:warning:` **Note:** In previous versions (``<0.12.0``) making dual architecture binaries was
+    performed with the ``delocate-fuse`` command. This commannd would overwrite the
+    first wheel passed in by default. This led to the user needing to rename the
+    wheel to correctly describe what platforms it supported. For this and other
+    reasons, wheels created with this were often incorrect. From version ``0.12.0``
+    and on, the ``delocate-fuse`` command has been removed and replaced with
+    ``delocate-merge``. The ``delocate-merge`` command will create a new wheel with an
+    automatically generated name based on the wheels that were merged together.
+    There is no need to perform any further changes to the merged wheel's name. If
+    the old behavior is needed (not recommended), pin the version to
+    ``delocate==0.11.0``.
+
 Troubleshooting
 ===============
 
diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index bd36dd03..b137e14d 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -1,43 +1,25 @@
 #!/usr/bin/env python3
 """Fuse two (probably delocated) wheels.
 
-Writes to a new wheel with an automatically determined name by default.
+Command is no longer available. To fuse two wheels together use
+'delocate-merge'. NOTE: 'delocate-merge' does not overwrite the first wheel. It
+creates a new wheel with an automatically determined name. If the old behavior
+is needed (not recommended), pin the version to 'delocate==0.11.0'.
 """
 
 # vim: ft=python
 from __future__ import annotations
 
-from argparse import ArgumentParser
-from pathlib import Path
-
-from delocate.cmd.common import common_parser, verbosity_config
-from delocate.fuse import fuse_wheels
-
-parser = ArgumentParser(description=__doc__, parents=[common_parser])
-parser.add_argument(
-    "wheels", nargs=2, metavar="WHEEL", type=str, help="Wheels to fuse"
-)
-parser.add_argument(
-    "-w",
-    "--wheel-dir",
-    action="store",
-    type=str,
-    help="Directory to store delocated wheels"
-    " (default is to store in the same directory as the 1st WHEEL with an"
-    " automatically determined name).",
-)
-
 
 def main() -> None:  # noqa: D103
-    args = parser.parse_args()
-    verbosity_config(args)
-    wheel1, wheel2 = [Path(wheel).resolve(strict=True) for wheel in args.wheels]
-    if args.wheel_dir is not None:
-        out_wheel = Path(args.wheel_dir).resolve()
-        out_wheel.mkdir(parents=True, exist_ok=True)
-    else:
-        out_wheel = None
-    fuse_wheels(wheel1, wheel2, out_wheel)
+    print(
+        "'delocate-fuse' is no longer available. To fuse two wheels together"
+        " use 'delocate-merge'. NOTE: 'delocate-merge' does not overwrite the"
+        " first wheel. It creates a new wheel with an automatically determined"
+        " name. If the old behavior is needed (not recommended), pin the"
+        " version to 'delocate==0.11.0'."
+    )
+    return 1
 
 
 if __name__ == "__main__":
diff --git a/delocate/cmd/delocate_merge.py b/delocate/cmd/delocate_merge.py
new file mode 100755
index 00000000..bd36dd03
--- /dev/null
+++ b/delocate/cmd/delocate_merge.py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+"""Fuse two (probably delocated) wheels.
+
+Writes to a new wheel with an automatically determined name by default.
+"""
+
+# vim: ft=python
+from __future__ import annotations
+
+from argparse import ArgumentParser
+from pathlib import Path
+
+from delocate.cmd.common import common_parser, verbosity_config
+from delocate.fuse import fuse_wheels
+
+parser = ArgumentParser(description=__doc__, parents=[common_parser])
+parser.add_argument(
+    "wheels", nargs=2, metavar="WHEEL", type=str, help="Wheels to fuse"
+)
+parser.add_argument(
+    "-w",
+    "--wheel-dir",
+    action="store",
+    type=str,
+    help="Directory to store delocated wheels"
+    " (default is to store in the same directory as the 1st WHEEL with an"
+    " automatically determined name).",
+)
+
+
+def main() -> None:  # noqa: D103
+    args = parser.parse_args()
+    verbosity_config(args)
+    wheel1, wheel2 = [Path(wheel).resolve(strict=True) for wheel in args.wheels]
+    if args.wheel_dir is not None:
+        out_wheel = Path(args.wheel_dir).resolve()
+        out_wheel.mkdir(parents=True, exist_ok=True)
+    else:
+        out_wheel = None
+    fuse_wheels(wheel1, wheel2, out_wheel)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/delocate/tests/test_scripts.py b/delocate/tests/test_scripts.py
index 5553b623..096ac884 100644
--- a/delocate/tests/test_scripts.py
+++ b/delocate/tests/test_scripts.py
@@ -402,20 +402,26 @@ def _fix_break_fix(arch: Text) -> None:
 def test_fuse_wheels(script_runner: ScriptRunner) -> None:
     # Some tests for wheel fusing
     with InTemporaryDirectory():
-        # Wheels need proper wheel filename for delocate-fuse
+        # Wheels need proper wheel filename for delocate-merge
         to_wheel = "to_" + basename(PLAT_WHEEL)
         from_wheel = "from_" + basename(PLAT_WHEEL)
         zip2dir(PLAT_WHEEL, "to_wheel")
         zip2dir(PLAT_WHEEL, "from_wheel")
         dir2zip("to_wheel", to_wheel)
         dir2zip("from_wheel", from_wheel)
-        script_runner.run(["delocate-fuse", to_wheel, from_wheel], check=True)
+        # Make sure delocate-fuse returns a non-zero exit code, it is no longer
+        # supported
+        result = script_runner.run(
+            ["delocate-fuse", to_wheel, from_wheel], check=True
+        )
+        assert result.returncode != 0
+        script_runner.run(["delocate-merge", to_wheel, from_wheel], check=True)
         zip2dir(to_wheel, "to_wheel_fused")
         assert_same_tree("to_wheel_fused", "from_wheel")
         # Test output argument
         os.mkdir("wheels")
         script_runner.run(
-            ["delocate-fuse", to_wheel, from_wheel, "-w", "wheels"],
+            ["delocate-merge", to_wheel, from_wheel, "-w", "wheels"],
             check=True,
         )
         zip2dir(pjoin("wheels", to_wheel), "to_wheel_refused")
diff --git a/pyproject.toml b/pyproject.toml
index 5cb71aa6..2dc95453 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,6 +35,7 @@ classifiers = [
 delocate-addplat = "delocate.cmd.delocate_addplat:main"
 delocate-fuse = "delocate.cmd.delocate_fuse:main"
 delocate-listdeps = "delocate.cmd.delocate_listdeps:main"
+delocate-merge = "delocate.cmd.delocate_merge:main"
 delocate-patch = "delocate.cmd.delocate_patch:main"
 delocate-path = "delocate.cmd.delocate_path:main"
 delocate-wheel = "delocate.cmd.delocate_wheel:main"

From 928a5be5c59464f3b7fb3ad242d55588d585375a Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Wed, 1 May 2024 22:46:11 -0400
Subject: [PATCH 19/21] Raise SystemExit directly to make mypy happy

---
 delocate/cmd/delocate_fuse.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/delocate/cmd/delocate_fuse.py b/delocate/cmd/delocate_fuse.py
index b137e14d..718ee274 100755
--- a/delocate/cmd/delocate_fuse.py
+++ b/delocate/cmd/delocate_fuse.py
@@ -19,7 +19,7 @@ def main() -> None:  # noqa: D103
         " name. If the old behavior is needed (not recommended), pin the"
         " version to 'delocate==0.11.0'."
     )
-    return 1
+    raise SystemExit(1)
 
 
 if __name__ == "__main__":

From 980a15b87da53d0361926ef219ddec8a22e4b444 Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Fri, 10 May 2024 19:37:27 -0400
Subject: [PATCH 20/21] Make out_wheel not optional

---
 delocate/cmd/delocate_merge.py |  9 ++++-----
 delocate/fuse.py               | 12 ++++--------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/delocate/cmd/delocate_merge.py b/delocate/cmd/delocate_merge.py
index bd36dd03..fdf096f1 100755
--- a/delocate/cmd/delocate_merge.py
+++ b/delocate/cmd/delocate_merge.py
@@ -32,11 +32,10 @@ def main() -> None:  # noqa: D103
     args = parser.parse_args()
     verbosity_config(args)
     wheel1, wheel2 = [Path(wheel).resolve(strict=True) for wheel in args.wheels]
-    if args.wheel_dir is not None:
-        out_wheel = Path(args.wheel_dir).resolve()
-        out_wheel.mkdir(parents=True, exist_ok=True)
-    else:
-        out_wheel = None
+    out_wheel = Path(
+        args.wheel_dir if args.wheel_dir is not None else wheel1.parent
+    ).resolve()
+    out_wheel.mkdir(parents=True, exist_ok=True)
     fuse_wheels(wheel1, wheel2, out_wheel)
 
 
diff --git a/delocate/fuse.py b/delocate/fuse.py
index 99186d76..7cfecd43 100644
--- a/delocate/fuse.py
+++ b/delocate/fuse.py
@@ -133,7 +133,7 @@ def fuse_trees(
 def fuse_wheels(
     to_wheel: str | PathLike,
     from_wheel: str | PathLike,
-    out_wheel: str | PathLike | None = None,
+    out_wheel: str | PathLike,
 ) -> Path:
     """Fuse `from_wheel` into `to_wheel`, write to `out_wheel`.
 
@@ -143,13 +143,11 @@ def fuse_wheels(
         The path of the wheel to fuse into.
     from_wheel : str or Path-like
         The path of the wheel to fuse from.
-    out_wheel : str or Path-like, optional
+    out_wheel : str or Path-like
         The path of the new wheel from fusion of `to_wheel` and `from_wheel`. If
         a full path is given, (including the filename) it will be used as is. If
         a directory is given, the fused wheel will be stored in the directory,
-        with the name of the wheel automatically determined. If no path is
-        given, the fused wheel will be stored in the same directory as
-        `to_wheel`, with the name of the wheel automatically determined.
+        with the name of the wheel automatically determined.
 
     Returns
     -------
@@ -161,9 +159,7 @@ def fuse_wheels(
     """
     to_wheel = Path(to_wheel).resolve(strict=True)
     from_wheel = Path(from_wheel).resolve(strict=True)
-    out_wheel = (
-        to_wheel.parent if out_wheel is None else Path(out_wheel).resolve()
-    )
+    out_wheel = Path(out_wheel)
     with tempfile.TemporaryDirectory() as temp_dir:
         to_wheel_dir = Path(temp_dir, "to_wheel")
         from_wheel_dir = Path(temp_dir, "from_wheel")

From a79cb51783f1dc2983befe0119f0707a6fa7a99d Mon Sep 17 00:00:00 2001
From: George Waters <gwatersdev@gmail.com>
Date: Fri, 10 May 2024 19:44:11 -0400
Subject: [PATCH 21/21] Fix delocate-fuse test

---
 delocate/tests/test_scripts.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/delocate/tests/test_scripts.py b/delocate/tests/test_scripts.py
index 096ac884..bd3a3ddd 100644
--- a/delocate/tests/test_scripts.py
+++ b/delocate/tests/test_scripts.py
@@ -411,9 +411,7 @@ def test_fuse_wheels(script_runner: ScriptRunner) -> None:
         dir2zip("from_wheel", from_wheel)
         # Make sure delocate-fuse returns a non-zero exit code, it is no longer
         # supported
-        result = script_runner.run(
-            ["delocate-fuse", to_wheel, from_wheel], check=True
-        )
+        result = script_runner.run(["delocate-fuse", to_wheel, from_wheel])
         assert result.returncode != 0
         script_runner.run(["delocate-merge", to_wheel, from_wheel], check=True)
         zip2dir(to_wheel, "to_wheel_fused")