FreeBSD has been doing this in our own package builds for two months
now.
https://svnweb.freebsd.org/ports?view=revision&revision=535771
ENV HOSTS=i686-unknown-freebsd
-ENV RUST_CONFIGURE_ARGS --enable-extended --disable-docs
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-profiler --disable-docs
ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS
ENV HOSTS=x86_64-unknown-freebsd
-ENV RUST_CONFIGURE_ARGS --enable-extended --disable-docs
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-profiler --disable-docs
ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS