[Pkg-rust-maintainers] Bug#1142711: rust-libcst : FTBFS on power systems with linkage error

[Fabian Grünbichler]

On Fri, 24 Jul 2026 18:33:41 +0530 Trupti <trupti at linux.ibm.com> wrote:
> Control: severity 1142711 serious
> 
> Hello,
> 
> 
> The package is falling because:
> 
> The [[bin]] "parse" target in Cargo.toml is compiled with
> feature="py" active, which enables pyo3/extension-module. Since
> pyo3 >= 0.27 this feature suppresses -lpython from the linker
> command. During cross-compilation no target Python interpreter
> is available, so all Python C-API symbols (PyTuple_New,
> _Py_Dealloc, PyGILState_Ensure, etc.) are unresolved -> link fails.
> 
> The binary is not shipped in any Debian package (bin=false in
> debcargo.toml), so the fix is simply to disable building it,
> the same way benchmarks are disabled in the existing
> debian/patches/disable-benches patch.

but doesn't that mean the `py` feature is broken? and why do you
mention cross compilation, the FTBFS is for a regular build and
from a quick glance I also don't see any of the CROSS variables
set in pyo3?