Issue when trying to compile on file libbitcoin_server_a-net.o #13993

Attempting to build from source and I am getting the below error.

Using Ubuntu 18.04 in Windows 10. Following these steps: https://github.com/bitcoin/bitcoin/blob/master/doc/build-windows.md#building-for-64-bit-windows

Any ideas on this issue? First time building from source, just wanting to build to understand Bitcoin more in-depth. I have ran into many issues and was able to research and find an answer and clear the errors, but I am stuck on this one.

  CXX      bitcoind-bitcoind.o
  CXX      libbitcoin_server_a-addrdb.o
  CXX      libbitcoin_server_a-addrman.o
  CXX      libbitcoin_server_a-bloom.o
  CXX      libbitcoin_server_a-blockencodings.o
  CXX      libbitcoin_server_a-chain.o
  CXX      libbitcoin_server_a-checkpoints.o
  CXX      consensus/libbitcoin_server_a-tx_verify.o
  CXX      libbitcoin_server_a-httprpc.o
  CXX      libbitcoin_server_a-httpserver.o
  CXX      index/libbitcoin_server_a-base.o
  CXX      index/libbitcoin_server_a-txindex.o
  CXX      libbitcoin_server_a-init.o
  CXX      libbitcoin_server_a-dbwrapper.o
  CXX      libbitcoin_server_a-merkleblock.o
  CXX      libbitcoin_server_a-miner.o
  CXX      libbitcoin_server_a-net.o
net.cpp: In member function ‘bool CConnman::BindListenPort(const CService&, std::__cxx11::string&, bool)’:
net.cpp:2133:31: error: ‘SOMAXLONN’ was not declared in this scope
     if (listen(hListenSocket, SOMAXLONN) == SOCKET_ERROR)
                               ^~~~~~~~~
net.cpp:2133:31: note: suggested alternative: ‘SOMAXCONN’
     if (listen(hListenSocket, SOMAXLONN) == SOCKET_ERROR)
                               ^~~~~~~~~
                               SOMAXCONN
Makefile:5994: recipe for target 'libbitcoin_server_a-net.o' failed
make[2]: *** [libbitcoin_server_a-net.o] Error 1
make[2]: Leaving directory '/home/user/bitcoin/src'
Makefile:10046: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/user/bitcoin/src'
Makefile:773: recipe for target 'all-recursive' failed
make: *** [all-recursive] Error 1

Where did you get the code from? https://github.com/bitcoin/bitcoin/blob/3c8d1ae15352d5c92d5903536c8fe07f771e97a0/src/net.cpp#L2133

git clone https://github.com/bitcoin/bitcoin.git

But I did move it around a few times before its final destination. Possibly corrupted code?

You can try git reset --hard and compile it again.

As pointed out by @ken2812221, the source has been modified in some way, as SOMAXLONN does not exist in the code base.