Hi, This is Jimmy from the ArchLinux RISC-V Team. The config.guess file contained in the source code is too old to build on the latest architecture, such as RISC-V. This can be fixed by generating new tarball by latest autotools. We propose a one-time fix for this via upstream, which benefits all downstream package maintainers. Thanks.
[Build Failed on RISC-V] Please consider updating autotool scripts
BUILD FAIL: configure cannot guess build type
BUILD FAIL: configure cannot guess build type
BUILD FAIL: configure cannot guess build type