A process hangs on Ubuntu sometimes

[peaceiris]

The problem is that Hugo hangs on runs-on: ubuntu-18.04 and 20.04 sometimes.

Hanging at hugo step sometimes · Issue #465 · peaceiris/actions-hugo

I tested some settings as follows:

• The building works well on local Ubuntu 18.04/20.04
• runs-on: macos-latest works well
• container.image: 'ubuntu:18.04' also hangs
• When I removed images, CSS, JavaScript, and HTML files from the user's content directory, then built it some times with a small set. It works well.

My questions:

• Does the Ubuntu VM of GitHub Actions runner has any limitation?
• Have anybody faced a problem like this with other tools or programs?
• Any ideas what I can try next to debug this?

Sorry for my ambiguous question.

[EnricoMi]

The VMs have only 2 CPUs / 4 vCPUs and around 7GB RAM. I managed to consistently hang them with make -j, which spawns unlimited number of parallel compile processes. This eventually brought the VM to an halt, without GitHub actions being able to cancel the job or retrieve logs.

[EnricoMi]

I just found out by running this command before the one that eventually hangs:

bash -c "while true; do pstree -uA; sleep 1; done &"

This requires psmisc to be installed (ubuntu-latest). It continuously shows all existing processes, every second, while running the subsequent commands.

[peaceiris]

In our case, the problem has been related to Hugo.

Closed by Release v0.91.2 · gohugoio/hugo
peaceiris/actions-hugo#465 (comment)