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: 
- ./_site/temata/energetika.html

  *  Build error (line 778)

     No item with slug 57-doprava-ve-meste
It shows there was an error while building file "./_site/temata/energetika.html" on line 778.