/usr/share/live/build/bootloaders/ is in live-build 3.0~a57-1ubuntu25.
This file is owned by root:root, with mode 0o755.
..
/usr/share/live/build/bootloaders/extlinux/
/usr/share/live/build/bootloaders/extlinux/extlinux.conf
/usr/share/live/build/bootloaders/extlinux/install.cfg
/usr/share/live/build/bootloaders/extlinux/live.cfg.in
/usr/share/live/build/bootloaders/extlinux/menu.cfg
/usr/share/live/build/bootloaders/extlinux/splash.svg.in
/usr/share/live/build/bootloaders/extlinux/stdmenu.cfg
/usr/share/live/build/bootloaders/extlinux/vesamenu.c32
/usr/share/live/build/bootloaders/isolinux/
/usr/share/live/build/bootloaders/isolinux/install.cfg
/usr/share/live/build/bootloaders/isolinux/isolinux.bin
/usr/share/live/build/bootloaders/isolinux/isolinux.cfg
/usr/share/live/build/bootloaders/isolinux/live.cfg.in
/usr/share/live/build/bootloaders/isolinux/menu.cfg
/usr/share/live/build/bootloaders/isolinux/splash.svg.in
/usr/share/live/build/bootloaders/isolinux/stdmenu.cfg
/usr/share/live/build/bootloaders/isolinux/vesamenu.c32
/usr/share/live/build/bootloaders/pxelinux/
/usr/share/live/build/bootloaders/pxelinux/install.cfg
/usr/share/live/build/bootloaders/pxelinux/live.cfg.in
/usr/share/live/build/bootloaders/pxelinux/menu.cfg
/usr/share/live/build/bootloaders/pxelinux/pxelinux.0
/usr/share/live/build/bootloaders/pxelinux/pxelinux.cfg/
/usr/share/live/build/bootloaders/pxelinux/pxelinux.cfg/default
/usr/share/live/build/bootloaders/pxelinux/splash.svg.in
/usr/share/live/build/bootloaders/pxelinux/stdmenu.cfg
/usr/share/live/build/bootloaders/pxelinux/vesamenu.c32
/usr/share/live/build/bootloaders/syslinux/
/usr/share/live/build/bootloaders/syslinux/install.cfg
/usr/share/live/build/bootloaders/syslinux/live.cfg.in
/usr/share/live/build/bootloaders/syslinux/menu.cfg
/usr/share/live/build/bootloaders/syslinux/splash.svg.in
/usr/share/live/build/bootloaders/syslinux/stdmenu.cfg
/usr/share/live/build/bootloaders/syslinux/syslinux.cfg
/usr/share/live/build/bootloaders/syslinux/vesamenu.c32