pygobject fails to build in Ubuntu 18.10

pygobject 3.28.2-1 and 3.29.2-1 fails to build in Ubuntu 18.10.

pygobject 3.28.2-1 does build successfully on Ubuntu 18.04 LTS. 3.29.2-1 does build successfully in Debian unstable.

I confirmed that the problem is reproducible in a local sbuild. I confirm that the test hang also happens with python 3.7.

By the way, I had to manually cancel the builds since they were still hanging after 20 hours.

Build log
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https://launchpad.net/ubuntu/+source/pygobject/3.29.2-1/+build/15263898

Build log excerpt
-----------------

I: pybuild base:217: cd /<<PKGBUILDDIR>>/.pybuild/cpython2_2.7/build; python2.7 -m pytest tests
============================= test session starts ==============================
platform linux2 -- Python 2.7.15, pytest-3.6.4, py-1.5.4, pluggy-0.6.0
rootdir: /<<PKGBUILDDIR>>, inifile:
collected 1374 items

tests/test_atoms.py ....... [ 0%]
tests/test_cairo.py ......................... [ 2%]
tests/test_docstring.py ...............x. [ 3%]
tests/test_error.py ............... [ 4%]
tests/test_everything.py Trace/breakpoint trap (core dumped)
E: pybuild pybuild:338: test: plugin distutils failed with: exit code=133: cd /<<PKGBUILDDIR>>/.pybuild/cpython2_2.7/build; python2.7 -m pytest tests
dh_auto_test: pybuild --test --test-pytest -i python{version} -p 2.7 returned exit code 13
make[1]: *** [debian/rules:29: override_dh_auto_test] Error 1
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
make: *** [debian/rules:22: binary] Error 2
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
RUN: /usr/share/launchpad-buildd/slavebin/in-target scan-for-processes --backend=chroot --series=cosmic --arch=amd64 PACKAGEBUILD-15263898
Scanning for processes to kill in build PACKAGEBUILD-15263898
Build killed with signal TERM after 150 minutes of inactivity