Dear Maintainer,
this was already reported and fixed a while ago, cf.
https://bugs.debian.org/1020277.
I can't say if the bug resurfaced lately, or if it was never really
fixed, as I had a workaround in place. However today I notice the bug is
still here, and easy to reproduce. Here are the steps:
```
cd <somewhere>
## chroot setup
sudo debootstrap sid sid
sudo tee << EOF /etc/schroot/chroot.d/sid-amd64-test.conf
[sid-amd64-test]
description=Debian sid/amd64
type=directory
directory=${PWD}/sid
union-type=overlay
users=${LOGNAME}
root-users=${LOGNAME}
source-users=${LOGNAME}
source-root-users=${LOGNAME}
EOF
ls -l sid/etc/resolv.conf # is a regular file
## install systemd-resolved in the chroot
schroot -c source:sid-amd64-test -u root -- apt update
schroot -c source:sid-amd64-test -u root -- apt install -y systemd-resolved
ls -l sid/etc/resolv.conf # is a symlink -> ../run/systemd/resolve/stub-resolv.conf
## the chroot is now broken
$ schroot -c source:sid-amd64-test -u root -- apt update
E: 20copyfiles: realpath: /run/schroot/mount/sid-amd64-test-[...]/run/systemd/resolve/stub-resolv.conf: No such file or directory
E: 20copyfiles: dirname: missing operand
E: 20copyfiles: Try 'dirname --help' for more information.
E: 20copyfiles: mkdir: missing operand
E: 20copyfiles: Try 'mkdir --help' for more information.
E: sid-amd64-test-[...]: Chroot setup failed: stage=setup-start
```
Best,
Arnaud