Switch boost to g++ again, see if that helps building it correctly.

boost/Makefile

@@ -16,8 +16,9 @@ impl:
 	mkdir -p target && \
 	CXX=$$(which c++) ./bootstrap.sh --prefix=$$PWD/target/ --with-toolset=clang && \
 	./b2 clean && \
-	./b2 --prefix=/usr/local/src/starcry/boost_1_68_0/target/ toolset=clang cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++" || true
+	./b2 --with-program_options --prefix=$$PWD/target/ toolset=clang
 	# ^ ||true because with clang I saw a few libraries not compile correctly, we can ignore those.
+	#./b2 --with-program_options --prefix=$$PWD/target/ toolset=clang cxxflags="-stdlib=libc++ -std=c++17" linkflags="-stdlib=libc++"
 
 package:
 	rm -rf out