Build vor TP-Link CPE510v1 failed

I'm trying to build a custom OpenWRT on a Debian Bullseye, but unfortunately it fails on

make -j1 V=s kernel_menuconfig

with this result:

make[4]: Leaving directory '/home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0-initial/fixincludes'
make[4]: Entering directory '/home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0-initial/gcc'
build/genautomata /home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0/gcc/common.md /home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0/gcc/config/mips/mips.md \
  insn-conditions.md > tmp-automata.c
/bin/bash: line 2: 526992 Killed                  build/genautomata /home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0/gcc/common.md /home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0/gcc/config/mips/mips.md insn-conditions.md > tmp-automata.c
make[4]: *** [Makefile:2345: s-automata] Error 137
make[4]: Leaving directory '/home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0-initial/gcc'
make[3]: *** [Makefile:4251: all-gcc] Error 2
make[3]: Leaving directory '/home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0-initial'
make[2]: *** [Makefile:37: /home/builder/openwrt/build_dir/toolchain-mips_24kc_gcc-8.4.0_musl/gcc-8.4.0-initial/.built] Error 2
make[2]: Leaving directory '/home/builder/openwrt/toolchain/gcc/initial'
time: toolchain/gcc/initial/compile#8.58#0.89#9.46
    ERROR: toolchain/gcc/initial failed to build.
make[1]: *** [toolchain/Makefile:97: toolchain/gcc/initial/compile] Error 1
make[1]: Leaving directory '/home/builder/openwrt'
make: *** [/home/builder/openwrt/include/toplevel.mk:230: toolchain/install] Error 2

Any idea what I'm doing wrong or what is missing?