Documenting the rough approach taken to rebuild this package from 2.7 to 3.8
This is a base for the future - not a verbatim guide.

Generate a build root in OBS and use as the basis of a working
chroot. osc chroot should work too.

Then set env variables for all the macros and in the spec replace the
%{} with ${} so cut'n'paste works :)

buildroot=/home/abuild/rpmbuild/BUILDROOT
_sourcedir=/home/abuild/rpmbuild/SOURCES
_builddir=/home/abuild/rpmbuild/BUILD
sa_root=${buildroot}/rpmlint-mini-1.1+git2-1.2.1.jolla.i386/opt
_bindir=/usr/bin
_libdir=/usr/lib
SOURCE100=${_sourcedir}/rpmlint-deps-2.7.txt
SOURCE101=${_sourcedir}/rpmlint.wrapper
SOURCE102=${_sourcedir}/rpmlint-mini.config
SOURCE103=${_sourcedir}/polkit-default-privs.config
# A tiny rpm to test with
SOURCE104=${_sourcedir}/basesystem-11+git1-1.11.2.noarch.rpm
SOURCE200=${_sourcedir}/rpmlint-mini-rpmlintrc
python_version=3.8
py_libdir=/usr/lib/python3.8
name=rpmlint-mini
__find_requires=echo
__find_provides=echo

A bit of dir setup is needed:

rm -rf $sa_root
mkdir -p ${sa_root}/usr/bin
mkdir -p ${sa_root}/usr/lib
mkdir -p ${sa_root}/etc/rpmlint
mkdir -p ${sa_root}/etc/pythonstart
cd ${_builddir}

Then manually work through the spec using cut'n'paste.


To rebuild the python 3 standalone first clear out all the old cruft

mv ${sa_root}/${py_libdir}/site-packages/ <to a safe location>
rm -rf ${sa_root}/${py_libdir}

Now restore ${sa_root}/${py_libdir}/site-packages/ from <a safe location>

# Check python starts using
export PYTHONHOME=${saroot}/usr
and then run python3

Now test with an appropriately modified SOURCE100 and run rpmlint in a
loop. Add the missing files to SOURCE100 as needed. Note that some of
the modules beginning with _ are in lib-dynload (eg _sha256.*.so)

Sometimes exceptions hide the real missing import

while true; do ; for f in $(<${SOURCE100}); do  find -path "*/$f" -exec install -D {} ${sa_root}/${py_libdir}/{} \;; done; rpmlint; sleep 1; done

Continue this using the SA_ROOT and wrapper to test rpmlint