PythonExtension: use different bin dir on Windows (#45427)

lib/spack/spack/build_systems/python.py

@@ -17,7 +17,7 @@
 import llnl.util.filesystem as fs
 import llnl.util.lang as lang
 import llnl.util.tty as tty
-from llnl.util.filesystem import HeaderList, LibraryList
+from llnl.util.filesystem import HeaderList, LibraryList, join_path
 
 import spack.builder
 import spack.config
@@ -120,6 +120,12 @@ def skip_modules(self) -> Iterable[str]:
         """
         return []
 
+    @property
+    def bindir(self) -> str:
+        """Path to Python package's bindir, bin on unix like OS's Scripts on Windows"""
+        windows = self.spec.satisfies("platform=windows")
+        return join_path(self.spec.prefix, "Scripts" if windows else "bin")
+
     def view_file_conflicts(self, view, merge_map):
         """Report all file conflicts, excepting special cases for python.
         Specifically, this does not report errors for duplicate