Stefan Fiedler:

package/base/e2fsprogs/e2fsprogs.conf

@@ -22,6 +22,8 @@
 # --- ROCK-COPYRIGHT-NOTE-END ---
 
 libdir="$root/$multilib"
+sbindir="$root/sbin"
+var_append confopt " " "sbindir=${sbindir#$root}"
 
 # var_append extraconfopt " " '--with-root-prefix=$instroot/'
 var_append extraconfopt " " '--enable-fsck --enable-elf-shlibs --disable-evms'