[New-bugs-announce] [issue45909] sysconfig --generate-posix-vars creates wrong file when cross compiling

[Christian Heimes]

New submission from Christian Heimes <lists at cheimes.de>:

"sysconfig --generate-posix-vars" creates pybuilddir.txt and a platform-specific sysconfig data file like build/lib.linux-x86_64-3.11/_sysconfigdata__linux_x86_64-linux-gnu.py

When creating a cross-compile build of Python, sysconfig mixes data from the cross compile build and the host build. It creates a pybuilddir.txt and build/lib directory with correct values (e.g. wasm32-unknown-emscripten) but sysconfigdata file with name values from the host Python PYTHON_FOR_BUILD (e.g x86_64-unknown-linux-gnu). 

$ cat pybuilddir.txt 
build/lib.wasm32-unknown-emscripten-3.11

$ ls build/lib.wasm32-unknown-emscripten-3.11/_sysconfigdata*                           
build/lib.wasm32-unknown-emscripten-3.11/_sysconfigdata__linux_x86_64-linux-gnu.py

$ grep CC build/lib.wasm32-unknown-emscripten-3.11/_sysconfigdata__linux_x86_64-linux-gnu.py 
 'CC': 'gcc',

$ grep ^CC Makefile
CC=             emcc

----------
components: Build, Cross-Build
messages: 407141
nosy: Alex.Willmer, christian.heimes
priority: normal
severity: normal
status: open
title: sysconfig --generate-posix-vars creates wrong file when cross compiling
type: behavior
versions: Python 3.11

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue45909>
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