reproduce (this is a W=1 build): git remote add tytso-ext4 https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git git fetch tytso-ext4 dev git checkout tytso-ext4/dev b4 shazam https://lore.kernel.org/r/d906230bd4a1bc414926f6e9e38b75d41f2a6f47.1726034272.git.ojaswin@linux.ibm.com # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 olddefconfig make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/ext4/