[bug#71659] [PATCH] gnu: Add fastfetch.

[Dariqq]

Hi Richard,

Thanks for the patch. I've also been working on a package for fastfetch 
after I got the guix package detection into the upstream package but got 
a bit sidetracked by other things. Here is what I have in addition:

 - Removing the src/3rdparty dir with an origin snippet. This requires 
an extra package for yyjson which is very straightforward.
 - A lot more configure-flags similiar to the (waiting in newqueue) 
debian package:
        "-DBUILD_TESTS=ON"
        "-DINSTALL_LICENSE=OFF"
        "-DENABLE_SYSTEM_YYJSON=YES"
        "-DENABLE_PROPRIETARY_GPU_DRIVER_API=OFF"
        (string-append "-DCUSTOM_PCI_IDS_PATH="       
                #$(this-package-input "hwdata")
                "/share/hwdatay/pci.ids")
        (string-append "-DCUSTOM_AMDGPU_IDS_PATH="
                #$(this-package-input "libdrm")
                "/share/libdrm/amdgpu.ids")
- Enable the built tests
- For LM detection with logind "/var/run/systemd/sessions/" is used, 
however on (my) guix system that directory does not exist but is at 
"/run/systemd/sessions/" instead. Currently i have an extra substitute* 
to fix this in src/detection/lm/lm_linux.c but this might worth 
reporting to upstream. I havent got around to do this yet.
- Python as native input (to minify help.json)
- Enabling more of the optional dependencies
- The optional dependencies are dlopened at runtime. In order for 
fastfetch to find these I had to wrap fastfetch/flashfetch with 
LD_LIBRARY_PATH of the inputs.

What do you think?

Have a nice day,
Dariqq