I'm trying to make an Ubuntu app in Vala. I do have knowledge of C++ so the syntax isn't that difficult to learn. But I'm doing something wrong with the needed packages:
I need libsoup to communicate with an online API, and a json package. I tried to compile with this command:
valac --thread --pkg libsoup-2.4 --pkg json-glib-1.0 json-example.vala

I get following error:
/home/brendt/programs/vala/json-example.vala.c:9:26: fatal error: libsoup/soup.h: No such file or directory
compilation terminated.
error: cc exited with status 256
Compilation failed: 1 error(s), 0 warning(s)

So this makes me think I haven't installed that libsoup package in the correct place. I tried apt-get install, but than Ubuntu says the package is already installed. Than I tried cloning from git, but I don't really find a way to compile the source I get than..

anyone has some suggestions? I probably have to add a correct path somewhere, but I don't know where.
regards,
brendt