I tried to build G4Music (https://gitlab.gnome.org/neithern/g4music) following its instructions but I got many syntax errors.
As you can see GTK-4.0 is marked as not found. However I have installed GTK-4.4 dev packages. I'm using RHEL 9 as distro and I have all the packages required:
- gtk4.x86_64
- gtk4-devel.x86_64
- libvala.x86_64
- libvala-devel.x86_64
- vala.x86_64
- gstreamer1.x86_64
- gstreamer1-devel.x86_64
- libadwaita-1
I read that ? operator (question mark) is used to control null values and there's a lot of code using this operator. I have no experience with Vala language.
Do I missing some libraries? Why Vala compiler throw errors for this operator?
Thanks in advance