...

error: expected unqualified-id
extern "C" {
       ^
error: no member named 'fabsf' in the global namespace; did you mean 'labs'?
abs(float __lcpp_x) _NOEXCEPT {return ::fabsf(__lcpp_x);}

error: no member named 'ceilf' in the global namespace; did you mean 'ceil'?
inline _LIBCPP_INLINE_VISIBILITY float       ceil(float __lcpp_x) _NOEXCEPT       {return ::ceilf(__lcpp_x);}

error: no member named 'fabs' in the global namespace

error: no member named 'atanf' in the global namespace; did you mean 'atan'?

error: no member named 'cosf' in the global namespace; did you mean 'cos'?
...

fatal error: too many errors emitted, stopping now [-ferror-limit=]
2 warnings and 20 errors generated.
make[2]: *** [contracts/hello/hello.cpp.bc] Error 1
make[1]: *** [contracts/hello/CMakeFiles/hellodir/all] Error 2
make[1]: *** Waiting for unfinished jobs....
[ 90%] Built target eosio_chain
make: *** [all] Error 2

    >>>>>>>>>>>>>>>>>>>> MAKE building EOSIO has exited with the above error.

有時候可能因為合約 class 定義后面漏寫了分號導(dǎo)致上述出錯信息，不太判斷具體出錯地點，加上就??了。