There are multiple PRs and patches floating around that make RISC-V use
the /usr/lib64 directory, like other 64-bit ports. However, RISC-V
recommends to use /usr/lib64/lp64d for the Fedora ABI variant, and
various upstream projects follow that.
I think we should follow upstream, so that it's possible to use Fedora
to do upstream development without patching the sources, or elaborate
Fedora-specific configure invocations. The other reasons is to
future-proof the Fedora port against the arrival of an alternative ABI
that is not fully backwards-compatible (the same reason why the official
RISC-V documentation requires use of these paths).
Thanks,
Florian