[issue22724] byte-compile fails for cross-builds

[Andrew Aladjev]

Andrew Aladjev <aladjev.andrew at gmail.com> added the comment:

I've made a quick test of all patches provided. All patches have failed to fix it. The problem is more heavy than it looks like.

Please look at the following code:

PYTHON_FOR_BUILD='_PYTHON_PROJECT_BASE=$(abs_builddir) _PYTHON_HOST_PLATFORM=$(_PYTHON_HOST_PLATFORM) PYTHONPATH=$(shell test -f pybuilddir.txt && echo $(abs_builddir)/`cat pybuilddir.txt`:)$(srcdir)/Lib _PYTHON_SYSCONFIGDATA_NAME=_sysconfigdata_$(ABIFLAGS)_$(MACHDEP)_$(MULTIARCH) '${EPYTHON_FOR_BUILD:-${interp}}

It means that we will use "interp" to load cross compiled modules, env, etc from "_PYTHON_PROJECT_BASE". This code is broken by design. Loading of cross compiled modules, env, etc is not possible in general. For example you have different libc: glibc, musl, uclibc.

glibc -> cross compile -> glibc = loads fine.
musl -> cross compile -> musl = loads fine.
uclibc -> cross compile -> uclibc = loads fine.

glibc -> cross compile -> musl = failed to load.
glibc -> cross compile -> uclibc = failed to load.
musl -> cross compile -> glibc = failed to load.
musl -> cross compile -> uclibc = failed to load.
uclibc -> cross compile -> glibc = failed to load.
uclibc -> cross compile -> musl = failed to load.

Cross compilation doesn't mean only another arch, it means different libc, kernel headers, binutils and compiler. You will receive same issue while using clang toolchains.

Please assign this issue to python core developers. This issue can't be fixed by regular users without experience in python development. It requires complete change of cross compilation design.

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue22724>
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