Analyse following RPM build log snippet. Describe contents accurately, without speculation or suggestions for resolution.            
Your analysis must be as concise as possible, while keeping relevant information intact.
Snippet: 
Additional repo https_yum_theforeman_org_releas 2.1 kB/s | 245  B     00:00    
Errors during downloading metadata for repository 'https_yum_theforeman_org_releases_nightly_el8_x86_64':
  - Status code: 404 for https://yum.theforeman.org/releases/nightly/el8/x86_64/repodata/repomd.xml (IP: 2a04:4e42:400::561)
Error: Failed to download metadata for repo 'https_yum_theforeman_org_releases_nightly_el8_x86_64': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried

This line informs you that your system attempted to access an additional repository for the build process. The URL points to the Foreman project's nightly releases for Red Hat Enterprise Linux 8 (el8) and 64-bit architecture (x86_64).