As noted in the Compilers and Toolchains WG, RISC-V support in the various toolchains is still a work in progress and can require bringing together source patches and non-default branches from multiple upstream projects. This creates a barrier for developers wishing to participate in expanding the RISC-V software ecosystem.
As a member of RISE, Imagination provides a freely available set of pre-built RISC-V compilers, toolchains (including QEMU) together with a Visual Studio Code RISC-V IDE for Ubuntu, CentOS, Windows and macOS at https://github.com/imgtec-riscv/catapult-sdk.
For further information, please see the entry on the Compilers and Toolchains Working Group.