Tested
gapcoind branch v0.9.4 which now builds perfectly on Ubuntu 18.04 LTS server ...
Terminal window - copy and paste:
sudo apt-get update && sudo apt-get dist-upgrade
sudo apt-get install build-essential libtool autotools-dev autoconf pkg-config libssl-dev libevent-dev libboost-all-dev libgmp-dev libmpfr-dev
Berkeley DB:
wget http://download.oracle.com/berkeley-db/db-4.8.30.NC.tar.gz
echo '12edc0df75bf9abd7f82f821795bcee50f42cb2e5f76a6a281b85732798364ef db-4.8.30.NC.tar.gz' | sha256sum -c
tar -xvf db-4.8.30.NC.tar.gz
Berkeley DB compile:
cd db-4.8.30.NC/build_unix
mkdir -p build
BDB_PREFIX=$(pwd)/build
../dist/configure --disable-shared --enable-cxx --with-pic --prefix=$BDB_PREFIX
make install
cd ../..
Gapcoind download and compile:
git clone --branch v0.9.4-gap https://github.com/gapcoin-project/gapcoin.git
cd gapcoin
git submodule init
git submodule update
./autogen.sh
./configure CPPFLAGS="-I${BDB_PREFIX}/include/ -O2" LDFLAGS="-L${BDB_PREFIX}/lib/" --without-gui --without-miniupnpc --disable-tests
make
Strip gapcoind and gapcoin-cli:
cd src
strip gapcoind
strip gapcoin-cli
cd
Running Gapcoind:
cd gapcoin/src && ./gapcoind
....: To use the "-server" option, you must set a rpcpassword in the configuration file:
/root/.gapcoin/gapcoin.conf
It is recommended you use the following random password:
rpcuser=
rpcpassword=
(you do not need to remember this password)
The username and password MUST NOT be the same.
If the file does not exist, create it with owner-readable-only file permissions.
.....
Copy and paste:
rpcuser=gapcoinrpc
rpcpassword=
sudo nano /root/.gapcoin/gapcoin.conf
...
New screen session:
screen -S gapcoind
Run gapcoind:
cd gapcoin/src && ./gapcoind
Crtl + A + D (to exit screen)
cd gapcoin/src && ./gapcoind getinfo
etc.,
screen -r gapcoind (returns to screen session)

-
https://youtu.be/yndq8jeSPc8