-march=native is not supported on aarch64?

[SvenDowideit]

So while I've been sick, I started setting up my old SoftIron Overdrive 1000 (cortex-a57), and it too errors out with -march=native not supported when building with clang

root@38c67ba0082b:/app/reed-solomon-erasure# cargo build --features simd-accel
   Compiling libc v0.2.119
   Compiling cfg-if v1.0.0
   Compiling parking_lot_core v0.8.5
   Compiling smallvec v1.8.0
   Compiling cc v1.0.73
   Compiling scopeguard v1.1.0
   Compiling libm v0.2.2
   Compiling spin v0.9.2
   Compiling instant v0.1.12
   Compiling lock_api v0.4.6
   Compiling reed-solomon-erasure v5.0.1 (/app/reed-solomon-erasure)
   Compiling parking_lot v0.11.2
The following warnings were emitted during compilation:

warning: clang: error: the clang compiler does not support '-march=native'

error: failed to run custom build command for `reed-solomon-erasure v5.0.1 (/app/reed-solomon-erasure)`

Caused by:
  process didn't exit successfully: `/app/reed-solomon-erasure/target/debug/build/reed-solomon-erasure-830a07e817013591/build-script-build` (exit status: 1)
  --- stdout
  TARGET = Some("aarch64-unknown-linux-gnu")
  HOST = Some("aarch64-unknown-linux-gnu")
  CC_aarch64-unknown-linux-gnu = None
  CC_aarch64_unknown_linux_gnu = None
  HOST_CC = None
  CC = None
  CFLAGS_aarch64-unknown-linux-gnu = None
  CFLAGS_aarch64_unknown_linux_gnu = None
  HOST_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  CARGO_CFG_TARGET_FEATURE = None
  running: "cc" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "-Wall" "-Wextra" "-march=native" "-std=c11" "-o" "/app/reed-solomon-erasure/target/debug/build/reed-solomon-erasure-8082f4ad792d2b16/out/simd_c/reedsolomon.o" "-c" "simd_c/reedsolomon.c"
  cargo:warning=clang: error: the clang compiler does not support '-march=native'
  exit status: 1

  --- stderr


  error occurred: Command "cc" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "-Wall" "-Wextra" "-march=native" "-std=c11" "-o" "/app/reed-solomon-erasure/target/debug/build/reed-solomon-erasure-8082f4ad792d2b16/out/simd_c/reedsolomon.o" "-c" "simd_c/reedsolomon.c" with args "cc" did not execute successfully (status code exit status: 1).


warning: build failed, waiting for other jobs to finish...
error: build failed

removing the target_os = "macos", seems to fix it for this box