[Buildroot] mkfs.jffs2 error

[Darik Horn]

 > I get an error "..../default.script" file not found.

The filesystem scripts sometimes try to pack the udhcp files even if 
CONFIG_APP_UDHCPC is not set, which is a bug.

The quick fix is:

$ mkdir -p project_build_*/*/root/usr/share/udhcpc/
$ touch project_build_*/*/root/usr/share/udhcpc/default.script

You should provide more of the error transcript to get better help sooner.