When using --installroot=, expired_repos.json is written inside the install root instead of outside of it

[DaanDeMeyer]

When using https://github.com/systemd/mkosi/ to build images with dnf, expired_repos.json is written inside the install root instead of outside of it. The cache directory is configured to be outside of the install root. This can be reproduced by using dnf --installroot with a cache directory outside of the installroot.

I assume that rpm is chrooting into the installroot in the dnf process and that dnf tries to write expired_repos.json before the process exits the chroot.

[jan-kolarik]

True, it can be simply reproduced, like:

dnf --installroot /home/user/installroot/ --setopt=cachedir=/home/user/cache repoquery --releasever 40

This results in storing the expired_repos.json file inside the /home/user/installroot/home/user/cache instead in the /home/user/cache, where the other files are cached.