Merge pull request #1460 from hoodmane/chore-compute-platform

cibuildwheel/__main__.py

@@ -173,44 +173,22 @@ def main() -> None:
             log.warning(f"Can't delete temporary folder '{temp_dir}'")
 
 
-def build_in_directory(args: CommandLineArguments) -> None:
+def _compute_platform_only(only: str) -> PlatformName:
-    platform_option_value = args.platform or os.environ.get("CIBW_PLATFORM", "auto")
+    if "linux_" in only:
-    platform: PlatformName
+        return "linux"
-
+    if "macosx_" in only:
-    if args.only:
+        return "macos"
-        if "linux_" in args.only:
+    if "win_" in only or "win32" in only:
-            platform = "linux"
+        return "windows"
-        elif "macosx_" in args.only:
-            platform = "macos"
-        elif "win_" in args.only or "win32" in args.only:
-            platform = "windows"
-        else:
     print(
-                f"Invalid --only='{args.only}', must be a build selector with a known platform",
+        f"Invalid --only='{only}', must be a build selector with a known platform",
         file=sys.stderr,
     )
     sys.exit(2)
-        if args.platform is not None:
-            print(
-                "--platform cannot be specified with --only, it is computed from --only",
-                file=sys.stderr,
-            )
-            sys.exit(2)
-        if args.archs is not None:
-            print(
-                "--arch cannot be specified with --only, it is computed from --only",
-                file=sys.stderr,
-            )
-            sys.exit(2)
-    elif platform_option_value != "auto":
-        if platform_option_value not in PLATFORMS:
-            print(f"cibuildwheel: Unsupported platform: {platform_option_value}", file=sys.stderr)
-            sys.exit(2)
 
-        platform = typing.cast(PlatformName, platform_option_value)
+
-    else:
+def _compute_platform_ci() -> PlatformName:
-        ci_provider = detect_ci_provider()
+    if detect_ci_provider() is None:
-        if ci_provider is None:
         print(
             textwrap.dedent(
                 """
@@ -224,11 +202,11 @@ def build_in_directory(args: CommandLineArguments) -> None:
         )
         sys.exit(2)
     if sys.platform.startswith("linux"):
-            platform = "linux"
+        return "linux"
     elif sys.platform == "darwin":
-            platform = "macos"
+        return "macos"
     elif sys.platform == "win32":
-            platform = "windows"
+        return "windows"
     else:
         print(
             'cibuildwheel: Unable to detect platform from "sys.platform" in a CI environment. You can run '
@@ -237,6 +215,37 @@ def build_in_directory(args: CommandLineArguments) -> None:
         )
         sys.exit(2)
 
+
+def _compute_platform(args: CommandLineArguments) -> PlatformName:
+    platform_option_value = args.platform or os.environ.get("CIBW_PLATFORM", "auto")
+
+    if args.only and args.platform is not None:
+        print(
+            "--platform cannot be specified with --only, it is computed from --only",
+            file=sys.stderr,
+        )
+        sys.exit(2)
+    if args.only and args.archs is not None:
+        print(
+            "--arch cannot be specified with --only, it is computed from --only",
+            file=sys.stderr,
+        )
+        sys.exit(2)
+
+    if platform_option_value not in PLATFORMS | {"auto"}:
+        print(f"cibuildwheel: Unsupported platform: {platform_option_value}", file=sys.stderr)
+        sys.exit(2)
+
+    if args.only:
+        return _compute_platform_only(args.only)
+    elif platform_option_value != "auto":
+        return typing.cast(PlatformName, platform_option_value)
+
+    return _compute_platform_ci()
+
+
+def build_in_directory(args: CommandLineArguments) -> None:
+    platform: PlatformName = _compute_platform(args)
     options = compute_options(platform=platform, command_line_arguments=args, env=os.environ)
 
     package_dir = options.globals.package_dir