Trouble installing libzmq3-dev on GitHub Actions workflows that use clustermq

[wlandau]

This is not explicitly related to the clustermq code base, but it is affecting targets because of the dependency on ZeroMQ through clustermq. I am having trouble installing libzmq3-dev on Ubuntu 18.04 on GitHub Actions. An example of the full error is at https://github.com/ropensci/targets/runs/2545335843#step:8:124, and I created a more minimal reproducible example at https://github.com/wlandau/libzmq-reprex. Switching to Ubuntu 20.04 does not work because of different errors: https://github.com/ropensci/targets/runs/2544918909?check_suite_focus=true#step:8:102.

[mschubert]

Maybe this helps? https://github.com/ropensci/rzmq/blob/master/.github/workflows/R-CMD-check.yaml

[wlandau]

Thanks @mschubert, I switched to Ubuntu 20.04 and it seems to work now.