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: 
"/usr/bin/perl" "/usr/share/perl5/vendor_perl/ExtUtils/xsubpp"  -typemap '/usr/share/perl5/ExtUtils/typemap' -typemap '/home/test/fedora/perl-EV/perl-EV-4.34-build/EV-4.34/typemap'  EV.xs > EV.xsc
Unrecognized escape \S passed through at (eval 77) line 2, <__ANONIO__> line 868.
EV.c: In function ‘XS_EV__Watcher_is_active’:
EV.c:1472:45: error: ‘stash_’ undeclared (first use in this function); did you mean ‘stash_io’?
 1472 |               && (SvSTASH (SvRV (ST(0))) == stash_" . (ev_watcher * =~ /ev_(S+)/, "int") . "
      |                                             ^~~~~~
      |                                             stash_io
xsubpp tool warns and a compiler exits with an error.