>   CXX      src/math/src_libbitcoin_la-hash.lo
> In file included from src/math/ec_keys.cpp:26:0:
> ./include/bitcoin/bitcoin/math/secp256k1_initializer.hpp:38:29: error:
> 'secp256k1_context_t' has not been declared
>      static void set_context(secp256k1_context_t** context, int flags);
>                              ^
> ./include/bitcoin/bitcoin/math/secp256k1_initializer.hpp:58:5: error:
> 'secp256k1_context_t' does not name a type
>      secp256k1_context_t* context();
>      ^
> ./include/bitcoin/bitcoin/math/secp256k1_initializer.hpp:62:5: error:
> 'secp256k1_context_t' does not name a type
>      secp256k1_context_t* context_;
>      ^
> src/math/ec_keys.cpp: In function 'libbitcoin::ec_point
> libbitcoin::secret_to_public_key(const ec_secret&, bool)':
> src/math/ec_keys.cpp:35:42: error: 'class
> libbitcoin::secp256k1_signing' has no member named 'context'
>      const auto signing_context = signing.context();
>                                           ^
> src/math/ec_keys.cpp: In function 'bool
> libbitcoin::verify_public_key(const ec_point&)':
> src/math/ec_keys.cpp:56:52: error: 'class
> libbitcoin::secp256k1_verification' has no member named 'context'
>      const auto verification_context = verification.context();
>                                                     ^
> src/math/ec_keys.cpp:58:49: error: 'secp256k1_ec_pubkey_verify' was
> not declared in this scope
>          static_cast<uint32_t>(public_key.size())) == 1;
>                                                  ^
> src/math/ec_keys.cpp: In function 'bool
> libbitcoin::verify_private_key(const ec_secret&)':
> src/math/ec_keys.cpp:74:52: error: 'class
> libbitcoin::secp256k1_verification' has no member named 'context'
>      const auto verification_context = verification.context();