unity4.7.2 to xcode9:Call to unavailable function 'system': not available on iOS

使用unity4.7.2导出xcode，适配ios11的时候，出现这个错误： Call to unavailable function 'system': not available on iOS 在xcode工程中的具体错误位置：classes/main.mm line 71 extern "C" int system$UNIX2003(const char* command) { return system(command); } When using unity4.7.2 to export xcode, the error occurred when ios11 was adapted： Call to unavailable function 'system': not available on iOS. Specific error location in xcode project：classes/main.mm line 71 extern "C" int system$UNIX2003(const char* command) { return system(command); }