I tried to build openwrt with Cake support according to this page:
https://www.bufferbloat.net/projects/codel/wiki/Cake/ , then I run make,
and it crashes. I then run make -j1 V=s as instructed by the make process,
and  is the last error message:

make[3]: Leaving directory
'/home/feanor/Development/Programming/openwrt/package/base-files'
make[3]: Entering directory
'/home/feanor/Development/Programming/openwrt/feeds/cero/net/kmod-sched-fq_pie'
make -C
/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/linux-4.4.14
HOSTCFLAGS="-O2
-I/home/feanor/Development/Programming/openwrt/staging_dir/host/include
-I/home/feanor/Development/Programming/openwrt/staging_dir/host/usr/include
-I/home/feanor/Development/Programming/openwrt/staging_dir/target-x86_64_musl-1.1.16/host/include
-Wall -Wmissing-prototypes -Wstrict-prototypes"
CROSS_COMPILE="x86_64-openwrt-linux-musl-" ARCH="x86" KBUILD_HAVE_NLS=no
KBUILD_BUILD_USER="" KBUILD_BUILD_HOST="" CONFIG_SHELL="bash" V=''
CC="x86_64-openwrt-linux-musl-gcc"
SUBDIRS="/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git"
modules
make[4]: Entering directory
'/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/linux-4.4.14'
  CC [M]
/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git/sch_fq_pie.o
/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git/sch_fq_pie.c:
In function 'fq_pie_change':
/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git/sch_fq_pie.c:820:2:
error: implicit declaration of function 'qdisc_tree_decrease_qlen'
[-Werror=implicit-function-declaration]
  qdisc_tree_decrease_qlen(sch, drop_count);
  ^
cc1: some warnings being treated as errors
make[5]: *** [scripts/Makefile.build:265:
/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git/sch_fq_pie.o]
Error 1
make[4]: *** [Makefile:1385:
_module_/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git]
Error 2
make[4]: Leaving directory
'/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/linux-4.4.14'
make[3]: *** [Makefile:43:
/home/feanor/Development/Programming/openwrt/build_dir/target-x86_64_musl-1.1.16/linux-x86_64/sched-fq_pie-2015-git/.built]
Error 2
make[3]: Leaving directory
'/home/feanor/Development/Programming/openwrt/feeds/cero/net/kmod-sched-fq_pie'
make[2]: *** [package/Makefile:197:
package/feeds/cero/kmod-sched-fq_pie/compile] Error 2
make[2]: Leaving directory '/home/feanor/Development/Programming/openwrt'
make[1]: *** [package/Makefile:193:
/home/feanor/Development/Programming/openwrt/staging_dir/target-x86_64_musl-1.1.16/stamp/.package_compile]
Error 2
make[1]: Leaving directory '/home/feanor/Development/Programming/openwrt'
make: *** [/home/feanor/Development/Programming/openwrt/include/
toplevel.mk:194: world] Error 2

If this is the wrong place for bug report please tell me as this is my
first time I use mailing list