[PATCH v2] python_pep517.bbclass: export _PYTHON_HOST_PLATFORM to match our cross-compile target

[Alejandro Hernandez <alhe@linux.microsoft.com>]

When the _PYTHON_HOST_PLATFORM environment variable is unset, the value falls
back to the build host architecture, therefore, python wheels get an incorrect
platform tag, setting it as an empty value is also not allowed on python > 3.14.

Set _PYTHON_HOST_PLATFORM as HOST_ARCH dependent so bitbake correctly tags wheels
depending on our cross-compile target, fixing reproducibility issues.

Assisted-by: AI - OpenAI
Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>
---
 meta/classes-recipe/python_pep517.bbclass | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/meta/classes-recipe/python_pep517.bbclass b/meta/classes-recipe/python_pep517.bbclass
index d6246af5c2..a3c7d704d6 100644
--- a/meta/classes-recipe/python_pep517.bbclass
+++ b/meta/classes-recipe/python_pep517.bbclass
@@ -30,6 +30,10 @@ PEP517_INSTALL_PYTHON:class-native = "nativepython3"
 # pypa/installer option to control the bytecode compilation
 INSTALL_WHEEL_COMPILE_BYTECODE ?= "--compile-bytecode=0"
 
+# Python wheels are tagged with the HOST platform when built, use HOST_ARCH
+# since we are cross-compiling, avoiding incorrect host or an empty tag
+export _PYTHON_HOST_PLATFORM = "linux-${HOST_ARCH}"
+
 # PEP517 doesn't have a specific configure step, so set an empty do_configure to avoid
 # running base_do_configure.
 python_pep517_do_configure () {
-- 
2.43.0