I tried to rebuild qpid-proton against openssl 4 and noticed that it
doesn't build right now at all:

| make[3]: Leaving directory '/build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build'
| make  -f python/CMakeFiles/cproton.dir/build.make python/CMakeFiles/cproton.dir/build
| make[3]: Entering directory '/build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build'
| [ 99%] Building C object python/CMakeFiles/cproton.dir/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c.o
| cd /build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build/python && /usr/bin/x86_64-linux-gnu-gcc -Dcproton_EXPORTS -I/build/reproducible-path/qpid-proton-0.37.0/.pybuild/c python3_3.14/build/c/include -I/usr/include/python3.14 -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/build/reproducible-path/qpid-proton-0.37.0=. -fstack-protector-strong - fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -Wdate-time -D_FORTIFY_SOURCE=2 -fvisibility=hidden -std=c99 -fPIC -MD -MT python/CMakeFiles/cproton.dir/CMakeFiles/c proton.dir/cprotonPYTHON_wrap.c.o -MF CMakeFiles/cproton.dir/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c.o.d -o CMakeFiles/cproton.dir/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c.o -c /build /reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build/python/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c
| /build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build/python/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c: In function ‘pn_pytracer’:
| /build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build/python/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c:3846:23: error: implicit declaration of function ‘PyString_FromStr ing’; did you mean ‘PyLong_FromString’? [-Wimplicit-function-declaration]
|  3846 |     PyObject *pymsg = PyString_FromString(message);
|       |                       ^~~~~~~~~~~~~~~~~~~
|       |                       PyLong_FromString
| /build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build/python/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c:3846:23: error: initialization of ‘PyObject *’ {aka ‘struct _objec t *’} from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
| make[3]: *** [python/CMakeFiles/cproton.dir/build.make:82: python/CMakeFiles/cproton.dir/CMakeFiles/cproton.dir/cprotonPYTHON_wrap.c.o] Error 1
| make[3]: Leaving directory '/build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build'
| make[2]: *** [CMakeFiles/Makefile2:3848: python/CMakeFiles/cproton.dir/all] Error 2
| make[2]: Leaving directory '/build/reproducible-path/qpid-proton-0.37.0/.pybuild/cpython3_3.14/build'
| make[1]: *** [Makefile:149: all] Error 2

Maybe this broke during python transition and PyUnicode_FromString()
would be the right thing to use.

Sebastian

This issue is caused by the removal of the Python 2 compatibility macros in version 4.5.0 of SWIG. [1] According to the SWIG authors, these macros were retained in the generated code (pyhead.swg) solely for user typemaps. All typemap using these macros are updated to call the Python 3 C API directly.

I submitted a patch for fixing the issue as a merge request at Salsa. [2]

Note that upstream has fixed the issue in commit e4aec3a5 [3], which appears to be included in version  0.39.0. So, updating the package to the latest upstream version (0.40.0) should also fix the FTBFS problem.

Best,

Rafael Laboissière

[1] https://github.com/swig/swig/commit/79f7a2b7cb7ddc256eba09c8770133148025171d
[2] https://salsa.debian.org/openstack-team/third-party/qpid-proton/-/merge_requests/3
[3] https://github.com/apache/qpid-proton/commit/e4aec3a53759e2caf3a5ba22efbc1aff5c662685

We believe that the bug you reported is fixed in the latest version of
qpid-proton, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1144962@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Thomas Goirand <zigo@debian.org> (supplier of updated qpid-proton package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Wed, 02 Sep 2026 14:10:55 +0200
Source: qpid-proton
Architecture: source
Version: 0.37.0-10
Distribution: unstable
Urgency: medium
Maintainer: Debian OpenStack <team+openstack@tracker.debian.org>
Changed-By: Thomas Goirand <zigo@debian.org>
Closes: 1144962
Changes:
 qpid-proton (0.37.0-10) unstable; urgency=medium
 .
   [ Rafael Laboissière ]
   * Add build-with-swig-4.5.0.patch (Closes: #1144962).
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