dnf versus yum As of Fedora 22[1] dnf has replaced yum as the default package manager. In the event you are building a kernel for an older system you will either have to install dnf or substitute yum for dnf and/or yumdownloader from the yum-utils package. Building a Kernel from the Fedora source tree Make sure you have installed all dependencies $ fedpkg clone kernel you will likely need to check