fix: error out if multiple wheels with the same name are produced

cibuildwheel/linux.py

@@ -11,6 +11,7 @@
 from .options import Options
 from .typing import OrderedDict, PathOrStr, assert_never
 from .util import (
+    AlreadyBuiltWheelError,
     BuildSelector,
     NonPlatformWheelError,
     find_compatible_wheel,
@@ -258,6 +259,10 @@ def build_on_docker(
 
             repaired_wheels = docker.glob(repaired_wheel_dir, "*.whl")
 
+            for repaired_wheel in repaired_wheels:
+                if repaired_wheel.name in {wheel.name for wheel in built_wheels}:
+                    raise AlreadyBuiltWheelError(repaired_wheel.name)
+
         if build_options.test_command and build_options.test_selector(config.identifier):
             log.step("Testing wheel...")
 

cibuildwheel/macos.py

@@ -18,6 +18,7 @@
 from .typing import Literal, PathOrStr, assert_never
 from .util import (
     CIBW_CACHE_PATH,
+    AlreadyBuiltWheelError,
     BuildFrontend,
     BuildSelector,
     NonPlatformWheelError,
@@ -410,6 +411,9 @@ def build(options: Options, tmp_path: Path) -> None:
 
                 repaired_wheel = next(repaired_wheel_dir.glob("*.whl"))
 
+                if repaired_wheel.name in {wheel.name for wheel in built_wheels}:
+                    raise AlreadyBuiltWheelError(repaired_wheel.name)
+
                 log.step_end()
 
             if build_options.test_command and build_options.test_selector(config.identifier):

cibuildwheel/util.py

@@ -372,6 +372,20 @@ def __init__(self) -> None:
         super().__init__(message)
 
 
+class AlreadyBuiltWheelError(Exception):
+    def __init__(self, wheel_name: str) -> None:
+        message = textwrap.dedent(
+            f"""
+            cibuildwheel: Build failed because a wheel named {wheel_name} was already generated in the current run.
+
+            If you expected another wheel to be generated, check your project configuration, or run
+            cibuildwheel with CIBW_BUILD_VERBOSITY=1 to view build logs.
+            """
+        )
+
+        super().__init__(message)
+
+
 def strtobool(val: str) -> bool:
     return val.lower() in {"y", "yes", "t", "true", "on", "1"}
 

cibuildwheel/windows.py

@@ -18,6 +18,7 @@
 from .typing import PathOrStr, assert_never
 from .util import (
     CIBW_CACHE_PATH,
+    AlreadyBuiltWheelError,
     BuildFrontend,
     BuildSelector,
     NonPlatformWheelError,
@@ -367,6 +368,9 @@ def build(options: Options, tmp_path: Path) -> None:
 
                 repaired_wheel = next(repaired_wheel_dir.glob("*.whl"))
 
+                if repaired_wheel.name in {wheel.name for wheel in built_wheels}:
+                    raise AlreadyBuiltWheelError(repaired_wheel.name)
+
             if build_options.test_command and options.globals.test_selector(config.identifier):
                 log.step("Testing wheel...")
                 # set up a virtual environment to install and test from, to make sure

test/test_same_wheel.py

@@ -0,0 +1,42 @@
+import subprocess
+from test import test_projects
+
+import pytest
+
+from . import utils
+
+basic_project = test_projects.new_c_project()
+basic_project.files[
+    "repair.py"
+] = """
+import shutil
+import sys
+from pathlib import Path
+
+wheel = Path(sys.argv[1])
+dest_dir = Path(sys.argv[2])
+platform = wheel.stem.split("-")[-1]
+name = f"spam-0.1.0-py2-none-{platform}.whl"
+dest = dest_dir / name
+dest_dir.mkdir(parents=True, exist_ok=True)
+if dest.exists():
+    dest.unlink()
+shutil.copy(wheel, dest)
+"""
+
+
+def test(tmp_path, capfd):
+    # this test checks that a generated wheel name shall be unique in a given cibuildwheel run
+    project_dir = tmp_path / "project"
+    basic_project.generate(project_dir)
+
+    with pytest.raises(subprocess.CalledProcessError):
+        utils.cibuildwheel_run(
+            project_dir,
+            add_env={
+                "CIBW_REPAIR_WHEEL_COMMAND": "python repair.py {wheel} {dest_dir}",
+            },
+        )
+
+    captured = capfd.readouterr()
+    assert "Build failed because a wheel named" in captured.err