`aur-install` hangs for 10+ minutes

[Mikle-Bond]

[root@8cc0854b304d /]# time fakeroot -- sh -c 'echo hello'
hello

real    13m23.007s
user    0m0.027s
sys     0m0.008s

This image is partially affected by a ~bug~ quirk in faked, where it tries to close all available file descriptors. When building packages, makepkg runs fakeroot, which in turn spawns faked, which dives into a loop, proportional to the value of ulimit --nofile. A possible default amount of those in my case was 1073741816:

root@photon # docker run --rm ghcr.io/greyltc-org/archlinux-aur:yay sh -c 'ulimit -n'
1073741816
root@photon # ulimit -n
1024
root@photon # docker run --rm archlinux sh -c 'ulimit -n'
1073741816
root@photon # docker run --rm alpine sh -c 'ulimit -n'
1073741816

Solution to this issue is mentioned here, it suggests setting ulimit yourself. Possible ways are:

• In run command: docker run --rm --ulimit nofile=1024:10240 -it ghcr.io/greyltc-org/archlinux-aur
• In build command: docker build --ulimit nofile=1024:10240 .
• In docker-compose: .services.myservice.ulimits.nofile = "1024:10240" (I can't find how to set this for build stages in docker-compose)
• For the daemon: systemctl edit containerd.service (and, probably, the same for docker.service)

[Service]
LimitNOFILE=65536

Note, that setting limits for daemons is not recommended for performance reasons.

To verify, that this works I've used this dockerfile:

FROM ghcr.io/greyltc-org/archlinux-aur
RUN timeout -v 30 aur-install kickstart-git

Where kickstart-git is one of the packages I found that has minimal dependencies almost no install steps. It hangs (and fails) after ==> Entering fakeroot environment... without ulimit, and succeeds with limits set.

I haven't seen that many mentions of this quirk. Probably, most of docker users do not encounter this problem because they do not use fakeroot/fakechroot in the building process. This image is the notable exception. So, maybe, mentioning this mitigation in the README would save some people a couple (dozens) of minutes of research?

I'd recommend adding a troubleshooting section with something like

docker run --rm ghcr.io/greyltc-org/archlinux-aur sh -c 'time aur-install kickstart-git'
# (should take about 10-20 seconds)

to see if docker installation is affected by this, and one example to set ulimits if it's needed.