building Debian package from Buster fails on Bookworm

Question

I need to use older version of linphone on Debian 12.

The version in bookworm is 4.4.10-3, and I actually need 3.12.0, which is available in Buster.

On my bookworm build machine, I changed the sources, and downloaded linphone-3.12.0 sources from buster. Then I switched sources back to bookworm, and installed any necessary dependencies.

Update with more details

I made some progress, and now I get much further in the compilation process. However, it fails eventually:

make[3]: Leaving directory '/mnt/src/deb/LINPHONE/linphone-3.12.0/obj-x86_64-linux-gnu'
[ 66%] Built target linphone-static
make[2]: Leaving directory '/mnt/src/deb/LINPHONE/linphone-3.12.0/obj-x86_64-linux-gnu'
make[1]: *** [Makefile:159: all] Error 2
make[1]: Leaving directory '/mnt/src/deb/LINPHONE/linphone-3.12.0/obj-x86_64-linux-gnu'
dh_auto_build: error: cd obj-x86_64-linux-gnu && make -j4 "INSTALL=install --strip-program=true" VERBOSE=1 returned exit code 2
make: *** [debian/rules:15: binary] Error 2
dpkg-buildpackage: error: fakeroot debian/rules binary subprocess returned exit status 2

The full build output here and debian/rules here

Answer 1

The build fails because of

Traceback (most recent call last):
  File "/mnt/src/deb/LINPHONE/linphone-3.12.0/wrappers/cpp/genwrapper.py", line 764, in <module>
    main()
  File "/mnt/src/deb/LINPHONE/linphone-3.12.0/wrappers/cpp/genwrapper.py", line 760, in main
    genwrapper.render_all()
  File "/mnt/src/deb/LINPHONE/linphone-3.12.0/wrappers/cpp/genwrapper.py", line 700, in render_all
    self.render(header, self.includedir + '/enums.hh')
  File "/mnt/src/deb/LINPHONE/linphone-3.12.0/wrappers/cpp/genwrapper.py", line 716, in render
    with open(tmppath, mode='rU') as f:
         ^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: invalid mode: 'rU'

Python 3 no longer has a “U” mode for open(). To fix this, add debian/patches/genwrapper.patch containing

Index: linphone-3.12.0/wrappers/cpp/genwrapper.py
===================================================================
--- linphone-3.12.0.orig/wrappers/cpp/genwrapper.py
+++ linphone-3.12.0/wrappers/cpp/genwrapper.py
@@ -713,7 +713,7 @@ class GenWrapper(object):
                content = ''
                with open(tmppath, mode='w') as f:
                        f.write(self.renderer.render(item))
-               with open(tmppath, mode='rU') as f:
+               with open(tmppath, mode='r') as f:
                        content = f.read()
                with open(path, mode='w') as f:
                        f.write(content)

and add it to debian/patches/series:

$ echo genwrapper.patch >> debian/patches/series