Maybe use the following instead?

_SYSROOT_LLVM_TRIPLE_aarch64=           aarch64-unknown-freebsd${_SYSROOT_VER:C/-RELEASE//}
_SYSROOT_LLVM_TRIPLE_armv7=             armv7-unknown-freebsd${_SYSROOT_VER:C/-RELEASE//}-gnueabihf
_SYSROOT_LLVM_TRIPLE_powerpc=           powerpc-unknown-freebsd${_SYSROOT_VER:C/-RELEASE//} # secure-plt
_SYSROOT_LLVM_TRIPLE_powerpc64=         powerpc64-unknown-freebsd${_SYSROOT_VER:C/-RELEASE//} # elfv2

Maybe create a variable GCC_VERSION and use it here instead?
Or use this:
GCC_VERSION= ${_SYSROOT_DIST_powerpc:[2]:C/-.*//}

Same as above.

sorry, gcc_version is not the best name... it returns gcc13:

make -V GCC_VERSION
gcc13

maybe GCC_EXEC or GCC_BIN?

That sounds misleading, because it's not actually executable or binary. Maybe _GCC_VERSION?

how about this:
GCC_VERSION= ${_SYSROOT_DIST_powerpc:[2]:C/gcc([0-9]+)-.*/\1/}

make -V GCC_VERSION
13

and go for _GCC_VERSION?
I still have the old gcc version in my Makefile, hence the 13.

make -V _GCC_VERSION returns : gcc14
This line should be

-C${STAGEDIR}${_SYSROOT} /usr/local/lib/${_GCC_VERSION}

make -V _GCC_VERSION returns : gcc14
This line should be

	@${RLN} ${STAGEDIR}${_SYSROOT}/usr/local/lib/${_GCC_VERSION}/libatomic.so \