ring fails to cross-compile to arm-unknown-linux-musleabihf

[casept]

error: failed to run custom build command for `ring v0.16.20`

Caused by:
  process didn't exit successfully: `/media/psf/Home/spline/splinelogo-server-ng/target/debug/build/ring-495cf840d1f530b9/build-script-build` (exit status: 101)
  --- stdout
  OPT_LEVEL = Some("0")
  TARGET = Some("arm-unknown-linux-musleabihf")
  HOST = Some("aarch64-unknown-linux-gnu")
  CC_arm-unknown-linux-musleabihf = None
  CC_arm_unknown_linux_musleabihf = None
  TARGET_CC = Some("/home/user/.cache/cargo-zigbuild/0.6.6/zigcc-arm-unknown-linux-musleabihf.sh")
  CFLAGS_arm-unknown-linux-musleabihf = None
  CFLAGS_arm_unknown_linux_musleabihf = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  CARGO_CFG_TARGET_FEATURE = None

  --- stderr
  running "/home/user/.cache/cargo-zigbuild/0.6.6/zigcc-arm-unknown-linux-musleabihf.sh" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "-march=armv6" "-marm" "-mfpu=vfp" "-I" "include" "-Wall" "-Wextra" "-pedantic" "-pedantic-errors" "-Wall" "-Wextra" "-Wcast-align" "-Wcast-qual" "-Wconversion" "-Wenum-compare" "-Wfloat-equal" "-Wformat=2" "-Winline" "-Winvalid-pch" "-Wmissing-field-initializers" "-Wmissing-include-dirs" "-Wredundant-decls" "-Wshadow" "-Wsign-compare" "-Wsign-conversion" "-Wundef" "-Wuninitialized" "-Wwrite-strings" "-fno-strict-aliasing" "-fvisibility=hidden" "-fstack-protector" "-g3" "-U_FORTIFY_SOURCE" "-DNDEBUG" "-c" "-o/media/psf/Home/spline/splinelogo-server-ng/target/arm-unknown-linux-musleabihf/debug/build/ring-4cb7192578057057/out/aesv8-armx-linux32.o" "/home/user/.cargo/registry/src/git.luolix.top-1ecc6299db9ec823/ring-0.16.20/pregenerated/aesv8-armx-linux32.S"
  info: Available CPUs for architecture 'arm':
   arm1020e
   arm1020t
   arm1022e
   arm10e
   arm10tdmi
   arm1136j_s
   arm1136jf_s
   arm1156t2_s
   arm1156t2f_s
   arm1176jz_s
   arm1176jzf_s
   arm710t
   arm720t
   arm7tdmi
   arm7tdmi_s
   arm8
   arm810
   arm9
   arm920
   arm920t
   arm922t
   arm926ej_s
   arm940t
   arm946e_s
   arm966e_s
   arm968e_s
   arm9e
   arm9tdmi
   baseline
   cortex_a12
   cortex_a15
   cortex_a17
   cortex_a32
   cortex_a35
   cortex_a5
   cortex_a53
   cortex_a55
   cortex_a57
   cortex_a7
   cortex_a72
   cortex_a73
   cortex_a75
   cortex_a76
   cortex_a76ae
   cortex_a77
   cortex_a78
   cortex_a78c
   cortex_a8
   cortex_a9
   cortex_m0
   cortex_m0plus
   cortex_m1
   cortex_m23
   cortex_m3
   cortex_m33
   cortex_m35p
   cortex_m4
   cortex_m55
   cortex_m7
   cortex_r4
   cortex_r4f
   cortex_r5
   cortex_r52
   cortex_r7
   cortex_r8
   cortex_x1
   cyclone
   ep9312
   exynos_m1
   exynos_m2
   exynos_m3
   exynos_m4
   exynos_m5
   generic
   iwmmxt
   krait
   kryo
   mpcore
   mpcorenovfp
   neoverse_n1
   neoverse_n2
   neoverse_v1
   sc000
   sc300
   strongarm
   strongarm110
   strongarm1100
   strongarm1110
   swift
   xscale

  error: Unknown CPU: 'armv6'
  thread 'main' panicked at 'execution failed', /home/user/.cargo/registry/src/git.luolix.top-1ecc6299db9ec823/ring-0.16.20/build.rs:656:9
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: build failed, waiting for other jobs to finish...
error: build failed

This same error also occurs for several other related ARMv6 targets.

Compiling for aarch64-unknown-linux-musl, x86_64-unknown-linux-musl and several other tested targets works fine.

System details:

$ cargo --version
cargo 1.59.0 (49d8809dc 2022-02-10)

$ rustup --version
rustup 1.24.3 (ce5817a94 2021-05-31)
info: This is the version for the rustup toolchain manager, not the rustc compiler.
info: The currently active `rustc` version is `rustc 1.59.0 (9d1b2106e 2022-02-23)`

$ lsb_release --all 
LSB Version:    :core-4.1-aarch64:core-4.1-noarch
Distributor ID: Fedora
Description:    Fedora release 35 (Thirty Five)
Release:        35
Codename:       ThirtyFive

[casept]

On second look, this is probably caused upstream by ziglang/zig#4911.