# prepare folders
$ mkdir ~/build/
$ cd ~/build/

# install build pkgs
> pacman -S devtools base-devel

# fetch sources
$ pkgctl repo clone --protocol=https linux
$ cd linux/

# modify build file to your needs
$ edit PKGBUILD

# eg. just the name of the kernel
$ sed -i 's/pkgbase\=linux/pkgbase\=linux-custom/g' PKGBUILD

$ sed -i 's/make\ htmldocs/make/g' ./PKGBUILD
$ sed -i 's/\"\$pkgbase\-docs"//g' ./PKGBUILD

# by using '-s' all dependency will be met
$ makepkg -s

$ cd src/linux-6.9.7
$ git branch --delete --force --verbose 6.9.7-arch1

# to receive missing keys from openpgp.org
$ gpg --keyserver \
  hkps://keys.openpgp.org \
  --recv-keys <KEY_ID>

# or to receive missing keys from ubuntu
$ gpg --keyserver \
  hkps://keyserver.ubuntu.com \
  --recv-keys <KEY_ID>