Log excerpt: : 
 # /usr/bin/systemd-nspawn -q -M e3d332f68bbb41a6a2cfa579c9ef17a8 -D /var/lib/mock/fedora-eln-x86_64-bootstrap-1706757715.140855/root -a --capability=cap_ipc_lock --rlimit=RLIMIT_NOFILE=10240 --capability=cap_ipc_lock --bind=/tmp/mock-resolv.1pqgkwq6:/etc/resolv.conf --console=pipe --setenv=TERM=vt100 --setenv=SHELL=/bin/bash --setenv=HOME=/var/lib/mock/fedora-eln-x86_64-1706757715.140855/root/installation-homedir --setenv=HOSTNAME=mock --setenv=PATH=/usr/bin:/bin:/usr/sbin:/sbin '--setenv=PROMPT_COMMAND=printf "\033]0;<mock-chroot>\007"' '--setenv=PS1=<mock-chroot> \s-\v\$ ' --setenv=LANG=C.UTF-8 --setenv=LC_MESSAGES=C.UTF-8 --setenv=SYSTEMD_NSPAWN_TMPFS_TMP=0 --setenv=SYSTEMD_SECCOMP=0 --resolv-conf=off /usr/bin/dnf-3 --installroot /var/lib/mock/fedora-eln-x86_64-1706757715.140855/root/ --releasever eln --setopt=deltarpm=False --setopt=allow_vendor_change=yes --allowerasing --disableplugin=local --disableplugin=spacewalk --disableplugin=versionlock install clang-rpm-macros clang compiler-rt libomp libomp-devel llvm --setopt=tsflags=nocontexts --setopt=tsflags=nocontexts --setopt=tsflags=nocontexts
No matches found for the following disable plugin patterns: local, spacewalk, versionlock
Copr repository                                  28 kB/s | 1.5 kB     00:00    
Additional repo https_kojipkgs_fedoraproject_or  59 kB/s | 3.8 kB     00:00    
Additional repo https_download_copr_fedorainfra  99 kB/s | 3.3 kB     00:00    
Fedora - ELN BaseOS - Developmental packages fo  35 kB/s | 2.3 kB     00:00    
Fedora - ELN AppStream - Developmental packages  61 kB/s | 2.3 kB     00:00    
Fedora - ELN CodeReady Linux Builders - Build p  63 kB/s | 2.3 kB     00:00    
Error: 
 Problem: cannot install the best candidate for the job
  - nothing provides clang = 13.0.0 needed by clang-rpm-macros-1-136.el115.noarch from https_download_copr_fedorainfracloud_org_results_fedora_llvm_team_clang_rpm_macros_fedora_releasever_basearch
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages
Comment: DNF reporting a problem with dependencies. Here in particular clang-rpm-macros depends on a clang v13.0.0 which doesn't exist in the build repositories.