[...]

as type 'STRLEN {aka long unsigned int}' [-Wformat=]
                                   res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
                                                   ^
/usr/lib64/perl5/5.26.1/x86_64-tld-linux-thread-multi/CORE/embed.h:64:44: note: in definition of macro 'av_push'
 #define av_push(a,b)  Perl_av_push(aTHX_ a,b)
                                            ^
FindRef.xs:27:18: note: in expansion of macro 'newSVpv'
     av_push (av, newSVpv (text, 0));    \
                  ^~~~~~~
FindRef.xs:236:35: note: in expansion of macro 'res_pair'
                                   res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
                                   ^~~~~~~~
FindRef.xs:236:51: warning: format '%d' expects argument of type 'int', but argument 4 has type 'STRLEN {aka long unsigned int}' [-Wformat=]
                                   res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
                                                   ^
/usr/lib64/perl5/5.26.1/x86_64-tld-linux-thread-multi/CORE/embed.h:64:44: note: in definition of macro 'av_push'
 #define av_push(a,b)  Perl_av_push(aTHX_ a,b)
                                            ^
FindRef.xs:27:18: note: in expansion of macro 'newSVpv'
     av_push (av, newSVpv (text, 0));    \
                  ^~~~~~~
FindRef.xs:236:35: note: in expansion of macro 'res_pair'
                                   res_pair (form ("an lvalue reference target (type '%c', ofs %d, len %d),",
                                   ^~~~~~~~
make: *** [Makefile:328: FindRef.o] Error 1
error: Bad exit status from /tmp/B.6WR24V/BUILD/tmp/rpm-tmp.71095 (%build)
RPM build errors:
    Bad exit status from /tmp/B.6WR24V/BUILD/tmp/rpm-tmp.71095 (%build)
ended at: Sat Apr 14 17:08:07 2018, done in 0:00:00.466120
error: No files produced.
mesg: ttyname failed: Inappropriate ioctl for device
+ chmod -R u+rwX /tmp/B.6WR24V/BUILD
+ rm -rf /tmp/B.6WR24V/tmp /tmp/B.6WR24V/BUILD
mesg: ttyname failed: Inappropriate ioctl for device
+ rm -rf /tmp/B.6WR24V
Begin-TLD-Builder-Info
Build-Time: user:0.73s sys:0.16s real:1.10s (faults io:0 non-io:75152)
End-TLD-Builder-Info