I have tried building librecmc on my Talos II, but I got the following error:
In file included from /usr/include/powerpc64le-linux-gnu/asm/sigcontext.h:14,
/usr/include/powerpc64le-linux-gnu/asm/elf.h:160:9: error: unknown type name '__vector128'
typedef __vector128 elf_vrreg_t;
make: *** [scripts/Makefile.host:118: tools/proftool] Error 1
make: *** [Makefile:1195: tools-only] Error 2
The same error exists on power8: https://dev.archive.openwrt.org/ticket/19040.html
What distro are you using? Which version of libreCMC are you trying to build? I have been building libreCMC on the Blackbird for the last 6 mo. without any issues. I have built on Ubuntu 18.04, Fedora 31 and CentOS 8 (required some patching, not related to this issue).
v1.4 does not build without a bunch of hacks. tools/mkimage, packages/libs/libjson-c,packages/network/services/odhcpd and a few others would need to be patched. Also, the gcc-7.4.0 toolchain was needed to get it to build, which could lead to other issues / bugs.
v1.5.x does build without any known issues and is the focus of development right now. I don't know if it would be worth the effort to fix this since not many people have access to Power 8 / 9 machines.