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: 
checking for GNU M4 that supports accurate traces... configure: error: no acceptable m4 could be found in $PATH.
Check for acceptable GNU M4 macro processor has failed. This is a problem since M4 is used by autoconf.