The wallet code uses Optional::emplace()
, which was only added in boost 1.56, see https://github.com/boostorg/optional/commit/2e583aaf30964afd66c1284aa71d0d8b42fa440d
So for 0.21.0 there are two options:
- Work around
emplace
and keep the minimum boost version below 1.56 - Require boost 1.56
0wallet/rpcwallet.cpp: In function ‘UniValue listsinceblock(const JSONRPCRequest&)’:
1wallet/rpcwallet.cpp:1560:16: error: ‘Optional<int>’ has no member named ‘emplace’
2 height.emplace();
3 ^
4wallet/rpcwallet.cpp:1561:19: error: ‘Optional<int>’ has no member named ‘emplace’
5 altheight.emplace();
6 ^