To compiling and running SerenityOS on linux Mint with kernel version "5.4.0-122-generic", qemu x86 has some isssus with this version of kernel. This version is too old for lastest version of qemu. to resolve this problems we just need to update linux kernel to newest version :
qemu error, when we runnig SerenityOs on 5.4.0-122-generic linux kernel :
qemu-system-i386: -gdb tcp:127.0.0.1:1234: gdbstub: KVM doesn't support guest debugging
To check current version on your Machine you can use following command inside your terminal: