trying to install libgraph

libgraph expects libguile.h to be in the standard include paths which it is not. The autoconf script should really find the correct locations (which I consider a build system bug) but it doesn't, so you need to add its include path to the preprocessor and linker flags. The standard approach would be:

sudo apt install guile-2.0-dev  # In case you didn't install it earlier
CPPFLAGS="$CPPFLAGS $(pkg-config --cflags-only-I guile-2.0)" \
  CFLAGS="$CFLAGS $(pkg-config --cflags-only-other guile-2.0)" \
  LDFLAGS="$LDFLAGS $(pkg-config --libs guile-2.0)" \
  ./configure
make

Alternatively you can build libgraph without Guile module support:

./configure --disable-guile
make

1. Make sure that you have basic compilers installed. For this run the command:

   sudo apt-get install build-essential

2. Install few packages that required. Run the command:

   sudo apt-get install libsdl-image1.2 libsdl-image1.2-dev guile-1.8 guile-1.8-dev libsdl1.2debian libart-2.0-dev libaudiofile-dev libesd0-dev libdirectfb-dev libdirectfb-extra libfreetype6-dev libxext-dev x11proto-xext-dev libfreetype6 libaa1 libaa1-dev libslang2-dev libasound2 libasound2-dev

3. Now download libgraph. Copy libgraph-1.0.2.tar.gz to your home folder. Right click on it and select "Extract Here". Then run following commands one by one.

   cd libgraph-1.0.2

   ./configure

   sudo make

   sudo make install

   sudo cp /usr/local/lib/libgraph.* /usr/lib