Nicole4740 I have never attempted to build a package under Solus. However, have you looked at the following:
Following is a post by Ikey in the old Solus forums that I copied into my Linux Tips database that might be useful as well.
======= Ikey Post Begin =======
Compiling Normal Things
If you're getting issues with compiling programs from source on Solus, due to missing dependencies, compiler appears broken, etc, make sure you install the development group! This is much like the build-essential package on Debian derived distributions.
sudo eopkg it -c system.devel
Compiling Kernel Things
If you're building a kernel module, you might get some "not found" errors for the kernel. You'll need system.devel as well as the headers for your kernel. Assuming you're running the LTS kernel, you'll install them like so:
sudo eopkg it linux-lts-headers
For Everything Else...
Most packages in Solus are split up into "nameOfTheThing" and "nameOfTheThing-devel". This -devel subpackage is what you actually need when you're trying to compile stuff. So for example, if a build is complaining that it cannot find x11.. you'd want libx11-devel.
When in doubt, search!
eopkg sr x11 --name | grep “\-devel”
======= Ikey Post End =======
You could also use the search function in the Solus Software Center to search for packages. Good luck!