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: 

src/libnm-glib-aux/nm-uuid.c:490:12: error: '_1' may be used uninitialized [-Werror=maybe-uninitialized
This is warning about uninitialized variable.