Building FOSSology

Install CMake if you haven't already (minimum 3.10 required)

    sudo apt install CMake # for Debian based systems

Since the new build system is still in review. You must fork FOSSology and pull the #2075 pull request branch. Once you are in FOSSology root, run these commands.
```
git fetch https://github.com/avinal/fossology avinal/feat/buildsystem:buildsystem
git checkout buildsystem
```
The first step towards building is to create a temporary directory for storing intermediate files and build artifacts. By convention we use a directory named build, but you can use any name. (NOTE: For testing do not use other names)
```
mkdir build
cd build
```
In the next steps, we will configure the CMake project and generate the required configurations. You can use several flags to control the build. Given below are the flags available for this project.

CMake Flags	Description	Default
-DCMAKE_INSTALL_PREFIX=<path>	Sets the install prefix.	`/usr/local`
-DAGENTS="agent1;agent2..."	Only configure these agents.	ALL AGENTS
-DOFFLINE=<ON/OFF>	Controls vendor generation, ON=NO	OFF
-DCMAKE_BUILD_TYPE=<type>	- `Debug`, `Release`, `RelWithDebInfo`,`MinSizeRel`	`Debug`
-DTESTING=<ON/OFF>	Controls testing config generation	OFF
-DMONOPACK=<ON/OFF>	Package adj2nest and ununpack seperately	OFF
-GNinja	Use Ninja instead of Unix Makefiles	Unix MakeFiles

There are lots of inbuilt CMake command-line options you can see them in the official documentation. Once you have chosen your flags we can now configure the project using the following commands.

# From build folder
cd <name-of-build-directory>
cmake <flags> ..

4 . The next step is to build the project. You can use parallel jobs to build faster. For more options you can type cmake --help or make --help or ninja --help.

# Common build command for all generators,
# Default number of parallel builds depends on generator used
cmake --build . --parallel <no-of-processes>

# For Unix Makefiles, no parallel build by default
make -j <no-of-processes>

# For Ninja, 8+ parallel build by default (depends on system)
ninja -j <no-of-processes>

Installing is also as easy as building. You can choose to install only certain components even if you have built the whole project. If you directly invoke the install command without building the project, it will automatically build the project first.
```
# For Unix Makefiles
make install

# For Ninja
ninja install
```
While testing has some issues, but most of the testing is working fine. For now, you must build and run any test from the FOSSology root directory only. You can choose to configure a single agent if you want to test one agent only. See ctest --help for controlling test runs.
```
# Common testing command
ctest --parallel <no-of-processes>

# For Unix Makefiles
make test

# For Ninja
ninja test
```
You can package FOSSology, the packaging currently lacks copyright and conf files. But for testing purposes, you can use the following commands. Similar to installing, if you run the package command without building the project, it will automatically build the project first. See cpack --help for more packaging options.
```
# Common testing command
cpack

# For Unix Makefiles
make package

# For Ninja
ninja package
```
Some targets are not built by default, you can manually trigger their build by running make ,target-name> or ninja <target-name>. You can list all the targets by running make help or ninja -t targets.
You can also use CMake EXtension for VS Code for seamlessly populating and building targets. Can also use gitpod.io for quick setup