not building

[lihshyang]

somehow make gives me this error:
...
...
make[3]: Entering directory `/home/aolx/devel/gg/src/util'
CXX digest.o
CXX util.o
CXX path.o
CXX pipe.o
CXX poller.o
CXX signalfd.o
digest.cc: In function ‘std::string digest::sha256(const string&, bool)’:
digest.cc:26:39: error: expected type-specifier before ‘Base64URLEncoder’
new Base64URLEncoder( new StringSink( ret ), false ) ) );
^
digest.cc: In function ‘std::string digest::gghash_to_hex(const string&)’:
digest.cc:47:23: error: expected type-specifier before ‘Base64URLDecoder’
new Base64URLDecoder( new HexEncoder( new StringSink( output ), false ) ) );
^
make[3]: *** [digest.o] Error 1

[sadjad]

You need libcrypto++-dev >= 4.5.3 to build gg. It's included in Ubuntu Zesty or newer, but for the others I think you need to build and install it from the source.