* new build flags or prefix
    CC perf.o
    CC builtin-annotate.o
    CC builtin-bench.o
    CC bench/sched-messaging.o
    CC bench/sched-pipe.o
    CC bench/mem-memcpy.o
    CC builtin-diff.o
    CC builtin-help.o
    CC builtin-sched.o
    CC builtin-buildid-list.o
    CC builtin-list.o
    CC builtin-record.o
    CC builtin-report.o
    CC builtin-stat.o
    CC builtin-timechart.o
    CC builtin-top.o
    CC builtin-trace.o
    CC builtin-probe.o
    CC builtin-kmem.o
    CC util/abspath.o
    CC util/alias.o
    CC util/config.o
    CC util/ctype.o
    CC util/debugfs.o
    CC util/environment.o
    CC util/event.o
    CC util/exec_cmd.o
    CC util/help.o
    CC util/levenshtein.o
    CC util/parse-options.o
    CC util/parse-events.o
    CC util/path.o
    CC util/rbtree.o
    CC util/bitmap.o
    CC util/hweight.o
    CC util/find_next_bit.o
    CC util/run-command.o
    CC util/quote.o
    CC util/strbuf.o
    CC util/string.o
    CC util/strlist.o
    CC util/usage.o
    CC util/wrapper.o
    CC util/sigchain.o
    CC util/symbol.o
util/symbol.c: In function ‘filename__read_build_id’:
util/symbol.c:1119: error: ‘GElf_Nhdr’ undeclared (first use in this function)
util/symbol.c:1119: error: (Each undeclared identifier is reported only once
util/symbol.c:1119: error: for each function it appears in.)
util/symbol.c:1119: error: ‘nhdr’ undeclared (first use in this function)
cc1: warnings being treated as errors
util/symbol.c:1120: error: ISO C90 forbids mixed declarations and code
util/symbol.c: In function ‘sysfs__read_build_id’:
util/symbol.c:1158: error: ‘GElf_Nhdr’ undeclared (first use in this function)
util/symbol.c:1158: error: expected ‘;’ before ‘nhdr’
util/symbol.c:1159: error: ISO C90 forbids mixed declarations and code
util/symbol.c:1161: error: ‘nhdr’ undeclared (first use in this function)
make: *** [util/symbol.o] Error 1