When using gcc 7 on macOS: ``` $ gcc-7 --version gcc-7 (Homebrew GCC 7.3.0) 7.3.0 ``` I see the following errors: ``` In file included from ../src/common/compress_zstd.c:29:0: /usr/local/Cellar/zstd/1.3.4//include/zstd.h:593:29: error: 'ZSTD_defaultCMem' defined but not used [-Werror=unused-const-variable=] static ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL }; /**< this constant defers to stdlib's functions */ ^~~~~~~~~~~~~~~~ /usr/local/Cellar/zstd/1.3.4//include/zstd.h:404:21: error: 'ZSTD_skippableHeaderSize' defined but not used [-Werror=unused-const-variable=] static const size_t ZSTD_skippableHeaderSize = 8; /* magic number + skippable frame length */ ^~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/zstd/1.3.4//include/zstd.h:403:21: error: 'ZSTD_frameHeaderSize_max' defined but not used [-Werror=unused-const-variable=] static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX; ^~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/zstd/1.3.4//include/zstd.h:402:21: error: 'ZSTD_frameHeaderSize_min' defined but not used [-Werror=unused-const-variable=] static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN; ^~~~~~~~~~~~~~~~~~~~~~~~ /usr/local/Cellar/zstd/1.3.4//include/zstd.h:401:21: error: 'ZSTD_frameHeaderSize_prefix' defined but not used [-Werror=unused-const-variable=] static const size_t ZSTD_frameHeaderSize_prefix = ZSTD_FRAMEHEADERSIZE_PREFIX; ^~~~~~~~~~~~~~~~~~~~~~~~~~~ ```