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