Spurious file present in / of current ucore-hci:stable

[yacoob]

 -rw-r--r--. 1 root root 37 Jan  1  1970 /40-rpmostree-pkg-usermod-qemu-kvm.conf

As far as I can tell, this is hci-specific - that is, ucore:stable doesn't have it. Looks like some generated file that ended up in / for some reason. This is for ucore-hci@sha256:141718bf7867efff7839b64f5c87d7dc5b0daeb84c3926ceabb5932560e3f6f5.

[bvitnik]

Hi. I can confirm that this file is also present in recent update of Bazzite so it is not specific to ucore. I don't remember seeing it before. I'm yet to try to pinpoint when exactly it appeared and where is it coming from.

[surdy]

There is more digging needed on this but I have a few leads.

I think this comes as a result of installing qemu along with some bug. Looks like such files with names like "40-rpmostree-pkg-usermod" would be created by rpm-ostree intercepting usermod command. https://github.com/coreos/rpm-ostree/blob/b36350680bda783865de02c40069ff327c29fcb2/rust/src/builtins/scriptlet_intercept/usermod.rs#L82.

Qemu posinstall has a useradd for qemu in group kvm https://github.com/repoforge/rpms/blob/master/specs/qemu/qemu.spec#L165. Which corresponds to "qemu kvm" in the file.

Two things I did not figure out

1. Why does it create a file corresponding to usermod and not useradd "35-rpmostree-pkg-user" file ? 
2. Why did file land in / instead of SYSUSRS_DIR (/usr/lib/sysusers.d/) ?

Perhaps someone can investigate further.