docker pull immortalwrt/opde:sdk
docker run -it --rm immortalwrt/opde:sdk zsh # or bash
export http_proxy= # [your proxy], do not use localhost or 127.0.0.1
export https_proxy=$http_proxy
opde feeds && opde config -a
make package/feeds/telephony/rtpengine/compile -j$(nproc) || make package/feeds/telephony/rtpengine/compile V=s

Applying ./patches/01-cflags.patch using plaintext: 
patching file lib/lib.Makefile
patching file daemon/Makefile
patching file recording-daemon/Makefile
patching file iptables-extension/Makefile

Applying ./patches/04-prevent-systemd-detection.patch using plaintext: 
patching file lib/lib.Makefile

Applying ./patches/200-openssl-deprecated.patch using plaintext: 
patching file daemon/dtls.c
patching file lib/ssllib.c
make[4]: Entering directory '/openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module'
make -C /openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204 M=/openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module O=/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204 modules
make[5]: Entering directory '/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204'
make[6]: Entering directory '/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204'
  CC [M]  /openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module/xt_RTPENGINE.o
  Building modules, stage 2.
  MODPOST 1 modules
  CC      /openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module/xt_RTPENGINE.mod.o
  LD [M]  /openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module/xt_RTPENGINE.ko
/openwrt/staging_dir/toolchain-aarch64_cortex-a72_gcc-8.4.0_musl/bin/aarch64-openwrt-linux-musl-ld: cannot open linker script file /openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204/arch/arm64/kernel/module.lds: No such file or directory
make[7]: *** [/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204/scripts/Makefile.modpost:129: /openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module/xt_RTPENGINE.ko] Error 1
make[6]: *** [/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204/Makefile:1548: modules] Error 2
make[6]: Leaving directory '/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204'
make[5]: *** [Makefile:146: sub-make] Error 2
make[5]: Leaving directory '/openwrt/build_dir/target-aarch64_cortex-a72_musl/linux-bcm27xx_bcm2711/linux-4.19.204'
make[4]: *** [Makefile:34: modules] Error 2
make[4]: Leaving directory '/openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/kernel-module'
make[3]: *** [Makefile:276: /openwrt/build_dir/target-aarch64_cortex-a72_musl/rtpengine-no-transcode/rtpengine-mr8.5.3.3/.built] Error 2