From 8e4e3c90602e96479214d29bac1ce122e6999679 Mon Sep 17 00:00:00 2001
From: Massimiliano Culpo <massimiliano.culpo@gmail.com>
Date: Wed, 9 Oct 2024 09:08:27 +0200
Subject: [PATCH] python: rework how we compute the "command" property (#46850)

Some Windows Python installations may store the Python exe in Scripts/
rather than the base directory. Update `.command` to search in both
locations on Windows. On all systems, the search is now done
recursively from the search root: on Windows, that is the base install
directory, and on other systems it is bin/.
---
 lib/spack/llnl/util/filesystem.py             |  1 +
 .../repos/builtin/packages/python/package.py  | 21 ++++++++++---------
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/lib/spack/llnl/util/filesystem.py b/lib/spack/llnl/util/filesystem.py
index 54ace7d42fa4cf..00bb270151908c 100644
--- a/lib/spack/llnl/util/filesystem.py
+++ b/lib/spack/llnl/util/filesystem.py
@@ -47,6 +47,7 @@
     "copy_mode",
     "filter_file",
     "find",
+    "find_first",
     "find_headers",
     "find_all_headers",
     "find_libraries",
diff --git a/var/spack/repos/builtin/packages/python/package.py b/var/spack/repos/builtin/packages/python/package.py
index cba63ece181b4c..5db16ec17504f8 100644
--- a/var/spack/repos/builtin/packages/python/package.py
+++ b/var/spack/repos/builtin/packages/python/package.py
@@ -858,14 +858,14 @@ def command(self):
         # * python
         #
         # in that order if using python@3.11.0, for example.
-        version = self.spec.version
-        for ver in [version.up_to(2), version.up_to(1), ""]:
-            if sys.platform != "win32":
-                path = os.path.join(self.prefix.bin, "python{0}".format(ver))
-            else:
-                path = os.path.join(self.prefix, "python{0}.exe".format(ver))
-            if os.path.exists(path):
-                return Executable(path)
+        suffixes = [self.spec.version.up_to(2), self.spec.version.up_to(1), ""]
+        file_extension = "" if sys.platform != "win32" else ".exe"
+        patterns = [f"python{ver}{file_extension}" for ver in suffixes]
+        root = self.prefix.bin if sys.platform != "win32" else self.prefix
+        path = find_first(root, files=patterns)
+
+        if path is not None:
+            return Executable(path)
 
         else:
             # Give a last try at rhel8 platform python
@@ -874,8 +874,9 @@ def command(self):
                 if os.path.exists(path):
                     return Executable(path)
 
-            msg = "Unable to locate {0} command in {1}"
-            raise RuntimeError(msg.format(self.name, self.prefix.bin))
+        raise RuntimeError(
+            f"cannot to locate the '{self.name}' command in {root} or its subdirectories"
+        )
 
     @property
     def config_vars(self):