ERROR: Missing binary: libpng/1.6.37:20b7137cd336076bcb33c847c2cf2edced0ce511
libpng/1.6.37: WARN: Can't find a 'libpng/1.6.37' package for the specified settings, options and dependencies:
- Settings: arch=x86_64, build_type=Debug, compiler=apple-clang, compiler.version=9.1, os=Macos
- Options: api_prefix=None, fPIC=True, shared=False, zlib:fPIC=True, zlib:minizip=False, zlib:shared=False
- Dependencies: zlib/1.2.11
- Requirements: zlib/1.Y.Z
- Package ID: 20b7137cd336076bcb33c847c2cf2edced0ce511

ERROR: Missing prebuilt package for 'libpng/1.6.37'
Try to build from sources with "--build=libpng"
Or read "http://docs.conan.io/en/latest/faq/troubleshooting.html#error-missing-prebuilt-package"