On 2018-01-14 meeting, the Council has decided that adding any new arch to Gentoo must be preceded by an RFC to gentoo-dev@ and creation of project page. At the same time, the Council has decided that existing arches that do not have a corresponding Gentoo project have one month (i.e. until the next Council meeting) to fulfill this requirement. The nios2 & riscv arches do not currently have a backing project. Furthermore, AFAICS there is not a single package in Gentoo having those keywords. If you are planning to continue working on support for those architectures within Gentoo, then please create a backing project for each of them separately, including the necessary mail alias and RFC to gentoo-dev@. Otherwise, please remove them from arch.list along with the relevant profile changes.
Unfortunately I missed that myself, but... The author of glibc risc-v support (which was merged in glibc-2.27) visited the FOSDEM Gentoo booth and asked about becoming a Gentoo developer. I've left a message with willikins and will also write an e-mail in a bit, and hope to hear back from him. So, please keep risc-v on hold for the moment.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=d6672e79bfd994039e5be15c8dca094429adf1b8 commit d6672e79bfd994039e5be15c8dca094429adf1b8 Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2018-02-11 18:45:56 +0000 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: 2018-02-11 18:53:32 +0000 profiles: Remove riscv arch Closes: https://bugs.gentoo.org/644754 profiles/arch.list | 1 - profiles/arch/base/make.defaults | 2 +- profiles/arch/base/use.mask | 1 - profiles/embedded/make.defaults | 2 +- 4 files changed, 2 insertions(+), 4 deletions(-) https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=dd3ad1f5f47838fdb9cf5ce3b4adb2eadac6358e commit dd3ad1f5f47838fdb9cf5ce3b4adb2eadac6358e Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2018-02-11 18:43:53 +0000 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: 2018-02-11 18:53:27 +0000 profiles: Remove nios2 arch Closes: https://bugs.gentoo.org/644754 profiles/arch.list | 1 - profiles/arch/base/make.defaults | 2 +- profiles/arch/base/use.mask | 1 - profiles/embedded/make.defaults | 2 +- 4 files changed, 2 insertions(+), 4 deletions(-) Additionally, it has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=5a6ce84d05a6180618aff797df4db18b80e26fdd commit 5a6ce84d05a6180618aff797df4db18b80e26fdd Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2018-02-11 18:45:17 +0000 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: 2018-02-11 18:53:29 +0000 profiles: Remove incomplete riscv profiles Bug: https://bugs.gentoo.org/644754 profiles/arch/riscv/make.defaults | 7 ------- profiles/arch/riscv/package.use.mask | 5 ----- profiles/arch/riscv/parent | 1 - profiles/arch/riscv/use.force | 2 -- profiles/default/linux/riscv/13.0/desktop/eapi | 1 - profiles/default/linux/riscv/13.0/desktop/parent | 2 -- profiles/default/linux/riscv/13.0/developer/eapi | 1 - profiles/default/linux/riscv/13.0/developer/parent | 2 -- profiles/default/linux/riscv/13.0/eapi | 1 - profiles/default/linux/riscv/13.0/parent | 2 -- profiles/default/linux/riscv/17.0/desktop/eapi | 1 - profiles/default/linux/riscv/17.0/desktop/parent | 2 -- profiles/default/linux/riscv/17.0/developer/eapi | 1 - profiles/default/linux/riscv/17.0/developer/parent | 2 -- profiles/default/linux/riscv/17.0/eapi | 1 - profiles/default/linux/riscv/17.0/parent | 2 -- profiles/default/linux/riscv/eapi | 1 - profiles/default/linux/riscv/parent | 3 --- profiles/profiles.desc | 5 ----- 19 files changed, 42 deletions(-) https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=496de51275ba34e4f50655d8ce9cfd86a287aad3 commit 496de51275ba34e4f50655d8ce9cfd86a287aad3 Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2018-02-11 18:42:41 +0000 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: 2018-02-11 18:52:40 +0000 profiles: Remove incomplete nios2 profiles Bug: https://bugs.gentoo.org/644754 profiles/arch/nios2/eapi | 1 - profiles/arch/nios2/make.defaults | 22 ---- profiles/arch/nios2/package.use.mask | 200 ------------------------------- profiles/arch/nios2/parent | 2 - profiles/arch/nios2/use.force | 2 - profiles/arch/nios2/use.mask | 175 --------------------------- profiles/default/linux/nios2/13.0/eapi | 1 - profiles/default/linux/nios2/13.0/parent | 2 - profiles/default/linux/nios2/17.0/eapi | 1 - profiles/default/linux/nios2/17.0/parent | 2 - profiles/default/linux/nios2/eapi | 1 - profiles/default/linux/nios2/parent | 3 - profiles/profiles.desc | 5 - 13 files changed, 417 deletions(-)}