Fail of the Ubuntu setup due to `testthat` failing with `segfault` :frowning_face:

[j-i-l]

The fail of the Ubuntu setup is due to testthat failing in some test with segfault ☹️ https://github.com/furrer-lab/abn/actions/runs/9910471997/job/27380922315#step:18:80 which is not directly related to the installation process, but should be addressed anyways.

Originally posted by @j-i-l in #126 (comment)

[j-i-l]

See also https://github.com/furrer-lab/abn/actions/runs/9914355193/job/27393273145#step:17:266 ff

[matteodelucchi]

Seems like ${CPPFLAGS}, ${PKG_CPPFLAGS} and ${PKG_LIBS} did not end up correctly in the configure file (see here: https://github.com/furrer-lab/abn/actions/runs/9910471997/job/27380922315#step:13:80). Maybe this has something to do with the above errors...

[j-i-l]

As far as I can tell the error occurs in forLoopContent and failing is the lme4::glmer call. (glmer is also mentioned in #62)