Unsupported or unrecognised Environment: UCRT64

[z-rui]

$ opam switch create msys2-ucrt64

<><> Installing new switch packages <><><><><><><><><><><><><><><><><><><><>  🐫
Switch invariant: ["msys2-ucrt64"]

<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫
∗ installed msys2-ucrt64.1
⬇ retrieved msys2.0.1.0  (cached)
[ERROR] The compilation of msys2.0.1.0 failed at "sh ./gen_config.sh msys2 UCRT64".

#=== ERROR while compiling msys2.0.1.0 ========================================#
# context     2.5.0 | win32/x86_64 | msys2-ucrt64.1 | https://opam.ocaml.org#b820e8c25e0dea7a5ce86f961c182a44938fa39a
# path        D:\opam\msys2-ucrt64\.opam-switch\build\msys2.0.1.0
# command     D:\msys64\usr\bin\sh.exe ./gen_config.sh msys2 UCRT64
# exit-code   2
# env-file    D:\opam\log\msys2-42592-210a74.env
# output-file D:\opam\log\msys2-42592-210a74.out
### output ###
# Unsupported or unrecognised Environment: UCRT64



<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><>  🐫
┌─ The following actions failed
│ λ build msys2 0.1.0
└─
┌─ The following changes have been performed
│ ∗ install msys2-ucrt64 1
└─
Switch initialisation failed: clean up? ('n' will leave the switch partially installed) [Y/n]

I think the problem is with gen_config.sh, the switch case doesn't include UCRT64 (note, the README mentions UCRT64 is supported).