The target passed to clang is wrong for aarch64-apple-darwin

[glandium]

cc-rs passes the rust target unchanged, but unfortunately, in the case of aarch64-apple-darwin, the clang target is different, and clang doesn't recognize aarch64-apple-darwin at all. The right target to use is arm64-apple-darwin.

[sebdanielsson]

Anyone working on this?

[lmtr0]

Hello there, any Status on this?

[dot-asm]

I for one have no problem compiling for M1. I don't see any unrecognized flags passed to cc. I do observe additional --target flag if I attempt to compile with CC environment variable set to clang, but it's correct arm64-apple-darwin. In other words this looks resolved...

[lmtr0]

No, it isn't, arm64-apple-darwin isn't a valid target

[root@52bd9e36c736 be]# cargo build --target arm64-apple-darwin
error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `rustc - --crate-name ___ --print=file-names --target arm64-apple-darwin --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=cfg` (exit status: 1)
  --- stderr
  error: Error loading target specification: Could not find specification for target "arm64-apple-darwin". Run `rustc --print target-list` for a list of built-in targets

however this does when the target doesn't need the flags:

[root@52bd9e36c736 be]# RUSTFLAGS="-C linker=o64h-clang" cargo build --target aarch64-apple-darwin
   Compiling be v0.1.0 (/be)
    Finished dev [unoptimized + debuginfo] target(s) in 0.96s

For example, when compinling ring the aarch64 target doesn't work because it gives this error:

[root@52bd9e36c736 be]# CC=o64h-clang cargo build --target aarch64-apple-darwin
    Updating crates.io index
   Compiling cc v1.0.73
   Compiling untrusted v0.7.1
   Compiling ring v0.16.20
error: failed to run custom build command for `ring v0.16.20`

Caused by:
  process didn't exit successfully: `/be/target/debug/build/ring-742f4d26dc21a850/build-script-build` (exit status: 101)
  --- stdout
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("o64h-clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")

  --- stderr
  running "o64h-clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/aesv8-armx-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/aesv8-armx-ios64.S"
  In file included from /root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/aesv8-armx-ios64.S:12:
  include/GFp/arm_arch.h:96:5: error: "unsupported ARM architecture"
  #   error "unsupported ARM architecture"
      ^
  1 error generated.
  thread 'main' panicked at 'execution failed', /root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/build.rs:656:9
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[root@52bd9e36c736 be]# 

[dot-asm]

No, it isn't, arm64-apple-darwin isn't a valid target

What I meant was that if I run env CC=clang cargo build on a M1 machine or env CC=clang cargo build --target=aarch64-apple-darwin on an x86 machine, cc-rs passes --target=arm64-apple-darwin to clang. This is with cc-rs 1.0.73.

[lmtr0]

Ah, got it, sorry I misunderstood. Btw I used o64-clang (for amd64 builds) instead of o64h-clang (for aarch64 builds) and somehow, it worked.

[root@52bd9e36c736 be]# CC=o64-clang RUSTFLAGS="-C linker=o64-clang -C link-args=-D__ARM_ARCH__" cargo build --target aarch64-apple-darwin
   Compiling untrusted v0.7.1
   Compiling ring v0.16.20
   Compiling be v0.1.0 (/be)
    Finished dev [unoptimized + debuginfo] target(s) in 3.27s
[root@52bd9e36c736 be]# file target/aarch64-apple-darwin/debug/be
target/aarch64-apple-darwin/debug/be: Mach-O 64-bit arm64 executable, flags:<NOUNDEFS|DYLDLINK|TWOLEVEL|PIE|HAS_TLV_DESCRIPTORS>

[dot-asm]

In other words cc-rs did nothing wrong. At least in the sense that it passed same flags as it would to generic clang [for MacOS]. Case can be dismissed.

[lmtr0]

for some weird reason, this works:

[root@52bd9e36c736 be]# CC=clang RUSTFLAGS="-C linker=o64h-clang -C link-args=-D__ARM_ARCH__" cargo build --target aarch64-apple-darwin
   Compiling ring v0.16.20
error: failed to run custom build command for `ring v0.16.20`

Caused by:
  process didn't exit successfully: `/be/target/debug/build/ring-742f4d26dc21a850/build-script-build` (exit status: 101)
  --- stdout
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")

  --- stderr
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/aesv8-armx-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/aesv8-armx-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/ghashv8-armx-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/ghashv8-armx-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/vpaes-armv8-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/vpaes-armv8-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/armv8-mont-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/armv8-mont-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/chacha-armv8-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/chacha-armv8-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/ecp_nistz256-armv8-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/ecp_nistz256-armv8-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/ghash-neon-armv8-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/ghash-neon-armv8-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/sha512-armv8-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/sha512-armv8-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/sha256-armv8-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/sha256-armv8-ios64.S"
  running "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-I" "include" "-Wall" "-Wextra" "-std=c1x" "-Wbad-function-cast" "-Wnested-externs" "-Wstrict-prototypes" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/aes_nohw.o" "crypto/fipsmodule/aes/aes_nohw.c"
  In file included from crypto/fipsmodule/aes/aes_nohw.c:15:
  In file included from include/GFp/aes.h:52:
  In file included from include/GFp/base.h:66:
  In file included from /usr/lib/clang/13.0.0/include/stdint.h:52:
  In file included from /usr/include/stdint.h:26:
  In file included from /usr/include/bits/libc-header-start.h:33:
  In file included from /usr/include/features.h:514:
  /usr/include/gnu/stubs.h:7:11: fatal error: 'gnu/stubs-32.h' file not found
  # include <gnu/stubs-32.h>
            ^~~~~~~~~~~~~~~~
  1 error generated.
  thread 'main' panicked at 'execution failed', /root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/build.rs:656:9
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[root@52bd9e36c736 be]# CC=o64h-clang RUSTFLAGS="-C linker=o64h-clang -C link-args=-D__ARM_ARCH__" cargo build --target aarch64-apple-darwin
   Compiling ring v0.16.20
   Compiling be v0.1.0 (/be)
    Finished dev [unoptimized + debuginfo] target(s) in 4.24s

but this doesn't:

[root@52bd9e36c736 be]# cargo clean
[root@52bd9e36c736 be]# CC=o64h-clang RUSTFLAGS="-C linker=o64h-clang -C link-args=-D__ARM_ARCH__" cargo build --target aarch64-apple-darwin
   Compiling cc v1.0.73
   Compiling untrusted v0.7.1
   Compiling ring v0.16.20
error: failed to run custom build command for `ring v0.16.20`

Caused by:
  process didn't exit successfully: `/be/target/debug/build/ring-742f4d26dc21a850/build-script-build` (exit status: 101)
  --- stdout
  OPT_LEVEL = Some("0")
  TARGET = Some("aarch64-apple-darwin")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_aarch64-apple-darwin = None
  CC_aarch64_apple_darwin = None
  TARGET_CC = None
  CC = Some("o64h-clang")
  CFLAGS_aarch64-apple-darwin = None
  CFLAGS_aarch64_apple_darwin = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")

  --- stderr
  running "o64h-clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=arm64-apple-darwin" "-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" "-gfull" "-DNDEBUG" "-c" "-o/be/target/aarch64-apple-darwin/debug/build/ring-bc471d909e7e38fa/out/aesv8-armx-ios64.o" "/root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/aesv8-armx-ios64.S"
  In file included from /root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/pregenerated/aesv8-armx-ios64.S:12:
  include/GFp/arm_arch.h:96:5: error: "unsupported ARM architecture"
  #   error "unsupported ARM architecture"
      ^
  1 error generated.
  thread 'main' panicked at 'execution failed', /root/.cargo/registry/src/github.com-1ecc6299db9ec823/ring-0.16.20/build.rs:656:9
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
[root@52bd9e36c736 be]# 

[dot-asm]

Still looks like it's between you and your C compiler... In other words, I still don't see cc-rs doing anything wrong...

[lmtr0]

HMmmmmmmm