`cc 1.0.85` breaks cross-compilation x86_64 Linux -> {x86_64,aarch64} Darwin

[rvolosatovs]

We use Zig as a C compiler and rust-lld as linker to cross-compile Rust from x86_64 (or aarch64) Linux to {x86_64,aarch64} Darwin.
Updating cc from 1.0.83 to 1.0.85 breaks compilation for these.

Not sure if that's caused by cc directly or whether that's a problem in Ring.

x86_64-unknown-linux-gnu -> aarch64-apple-darwin

 The following warnings were emitted during compilation:
 warning: ring@0.17.7: error: UnknownArchitecture
 error: failed to run custom build command for `ring v0.17.7`
 Caused by:
   process didn't exit successfully: `/build/source/target/release/build/ring-dff0a7997c328e11/build-script-build` (exit status: 1)
   --- stdout
   cargo:rerun-if-env-changed=RING_PREGENERATE_ASM
   cargo:rustc-env=RING_CORE_PREFIX=ring_core_0_17_7_
   OPT_LEVEL = Some("3")
   TARGET = Some("aarch64-apple-darwin")
   HOST = Some("x86_64-unknown-linux-gnu")
   cargo:rerun-if-env-changed=CC_aarch64-apple-darwin
   CC_aarch64-apple-darwin = Some("aarch64-apple-darwin-zigcc")
   running: "aarch64-apple-darwin-zigcc" "--version"
   exit status: 0
   cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
   CRATE_CC_NO_DEFAULTS = None
   DEBUG = Some("false")
   running: "xcrun" "--show-sdk-platform-version" "--sdk" "macosx"
   cargo:rerun-if-env-changed=CFLAGS_aarch64-apple-darwin
   CFLAGS_aarch64-apple-darwin = None
   cargo:rerun-if-env-changed=CFLAGS_aarch64_apple_darwin
   CFLAGS_aarch64_apple_darwin = None
   cargo:rerun-if-env-changed=TARGET_CFLAGS
   TARGET_CFLAGS = None
   cargo:rerun-if-env-changed=CFLAGS
   CFLAGS = None
   running: "aarch64-apple-darwin-zigcc" "--version"
   exit status: 0
   running: "xcrun" "--show-sdk-platform-version" "--sdk" "macosx"
   running: "aarch64-apple-darwin-zigcc" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "--target=arm64-apple-darwin" "-mmacosx-version-min=11.0" "-I" "include" "-I" "/build/source/target/aarch64-apple-darwin/release/build/ring-18a91eda96a80e50/out" "-Wall" "-Wextra" "-fvisibility=hidden" "-std=c1x" "-pedantic" "-Wall" "-Wextra" "-Wbad-function-cast" "-Wcast-align" "-Wcast-qual" "-Wconversion" "-Wenum-compare" "-Wfloat-equal" "-Wformat=2" "-Winline" "-Winvalid-pch" "-Wmissing-field-initializers" "-Wmissing-include-dirs" "-Wnested-externs" "-Wredundant-decls" "-Wshadow" "-Wsign-compare" "-Wsign-conversion" "-Wstrict-prototypes" "-Wundef" "-Wuninitialized" "-Wwrite-strings" "-gfull" "-DNDEBUG" "-o" "/build/source/target/aarch64-apple-darwin/release/build/ring-18a91eda96a80e50/out/fad98b632b8ce3cc-curve25519.o" "-c" "crypto/curve25519/curve25519.c"
   cargo:warning=error: UnknownArchitecture
   exit status: 1
   --- stderr
   error occurred: Command "aarch64-apple-darwin-zigcc" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "--target=arm64-apple-darwin" "-mmacosx-version-min=11.0" "-I" "include" "-I" "/build/source/target/aarch64-apple-darwin/release/build/ring-18a91eda96a80e50/out" "-Wall" "-Wextra" "-fvisibility=hidden" "-std=c1x" "-pedantic" "-Wall" "-Wextra" "-Wbad-function-cast" "-Wcast-align" "-Wcast-qual" "-Wconversion" "-Wenum-compare" "-Wfloat-equal" "-Wformat=2" "-Winline" "-Winvalid-pch" "-Wmissing-field-initializers" "-Wmissing-include-dirs" "-Wnested-externs" "-Wredundant-decls" "-Wshadow" "-Wsign-compare" "-Wsign-conversion" "-Wstrict-prototypes" "-Wundef" "-Wuninitialized" "-Wwrite-strings" "-gfull" "-DNDEBUG" "-o" "/build/source/target/aarch64-apple-darwin/release/build/ring-18a91eda96a80e50/out/fad98b632b8ce3cc-curve25519.o" "-c" "crypto/curve25519/curve25519.c" with args "aarch64-apple-darwin-zigcc" did not execute successfully (status code exit status: 1).

x86_64-unknown-linux-gnu -> x86_64-apple-darwin

 The following warnings were emitted during compilation:
 warning: ring@0.17.7: error: UnknownOperatingSystem
 error: failed to run custom build command for `ring v0.17.7`
 Caused by:
   process didn't exit successfully: `/build/source/target/release/build/ring-dff0a7997c328e11/build-script-build` (exit status: 1)
   --- stdout
   cargo:rerun-if-env-changed=RING_PREGENERATE_ASM
   cargo:rustc-env=RING_CORE_PREFIX=ring_core_0_17_7_
   OPT_LEVEL = Some("3")
   TARGET = Some("x86_64-apple-darwin")
   HOST = Some("x86_64-unknown-linux-gnu")
   cargo:rerun-if-env-changed=CC_x86_64-apple-darwin
   CC_x86_64-apple-darwin = Some("x86_64-apple-darwin-zigcc")
   running: "x86_64-apple-darwin-zigcc" "--version"
   exit status: 0
   cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
   CRATE_CC_NO_DEFAULTS = None
   DEBUG = Some("false")
   running: "xcrun" "--show-sdk-platform-version" "--sdk" "macosx"
   cargo:rerun-if-env-changed=CFLAGS_x86_64-apple-darwin
   CFLAGS_x86_64-apple-darwin = None
   cargo:rerun-if-env-changed=CFLAGS_x86_64_apple_darwin
   CFLAGS_x86_64_apple_darwin = None
   cargo:rerun-if-env-changed=TARGET_CFLAGS
   TARGET_CFLAGS = None
   cargo:rerun-if-env-changed=CFLAGS
   CFLAGS = None
   running: "x86_64-apple-darwin-zigcc" "--version"
   exit status: 0
   running: "xcrun" "--show-sdk-platform-version" "--sdk" "macosx"
   running: "x86_64-apple-darwin-zigcc" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "--target=x86_64-apple-darwin" "-mmacosx-version-min=10.7" "-I" "include" "-I" "/build/source/target/x86_64-apple-darwin/release/build/ring-e988c0c94f7e5625/out" "-Wall" "-Wextra" "-fvisibility=hidden" "-std=c1x" "-pedantic" "-Wall" "-Wextra" "-Wbad-function-cast" "-Wcast-align" "-Wcast-qual" "-Wconversion" "-Wenum-compare" "-Wfloat-equal" "-Wformat=2" "-Winline" "-Winvalid-pch" "-Wmissing-field-initializers" "-Wmissing-include-dirs" "-Wnested-externs" "-Wredundant-decls" "-Wshadow" "-Wsign-compare" "-Wsign-conversion" "-Wstrict-prototypes" "-Wundef" "-Wuninitialized" "-Wwrite-strings" "-gfull" "-DNDEBUG" "-o" "/build/source/target/x86_64-apple-darwin/release/build/ring-e988c0c94f7e5625/out/fad98b632b8ce3cc-curve25519.o" "-c" "crypto/curve25519/curve25519.c"
   cargo:warning=error: UnknownOperatingSystem
   exit status: 1
   --- stderr
   error occurred: Command "x86_64-apple-darwin-zigcc" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "--target=x86_64-apple-darwin" "-mmacosx-version-min=10.7" "-I" "include" "-I" "/build/source/target/x86_64-apple-darwin/release/build/ring-e988c0c94f7e5625/out" "-Wall" "-Wextra" "-fvisibility=hidden" "-std=c1x" "-pedantic" "-Wall" "-Wextra" "-Wbad-function-cast" "-Wcast-align" "-Wcast-qual" "-Wconversion" "-Wenum-compare" "-Wfloat-equal" "-Wformat=2" "-Winline" "-Winvalid-pch" "-Wmissing-field-initializers" "-Wmissing-include-dirs" "-Wnested-externs" "-Wredundant-decls" "-Wshadow" "-Wsign-compare" "-Wsign-conversion" "-Wstrict-prototypes" "-Wundef" "-Wuninitialized" "-Wwrite-strings" "-gfull" "-DNDEBUG" "-o" "/build/source/target/x86_64-apple-darwin/release/build/ring-e988c0c94f7e5625/out/fad98b632b8ce3cc-curve25519.o" "-c" "crypto/curve25519/curve25519.c" with args "x86_64-apple-darwin-zigcc" did not execute successfully (status code exit status: 1).

Refs bytecodealliance/wit-deps#118
For reference, the zigcc script is defined at https://github.com/rvolosatovs/nixify/blob/3e34d28daa53c41ae615360f4c106cc1771ae869/lib/rust/mkAttrs.nix#L297-L312

[NobodyXu]

Is it possible that zig doesn't support -mmacosx-version-min=10.7?

[BlackHoleFox]

@NobodyXu Why'd you yank the latest cc release? This seems like a much less severe (with no offense) problem then the last issue that broke all macOS builds from even the same host. This affects a far smaller subset of crates. That said I can still look at figuring out what broke,

[BlackHoleFox]

Interested to see how this even worked before. Is the problem xcrun or a shim isn't available on your host? cc's old versions ran xcrun as well but it appears your builds avoided that callpath by having SDKROOT set ahead of time.

Is it possible that zig doesn't support -mmacosx-version-min=10.7?

Seems unlikely? The aarch64-apple-darwin build also failed and that passes 11.0 instead of 10.7: -mmacosx-version-min=11.0"

It would be helpful to get a verbose cargo build log from your CI or local machines when this actually worked to compare the flags passed to zigcc. Not really familiar with how it works or Zig's target selection otherwise. That UnknownOperatingSystem error in the logs looks like it comes from zig but that's the furthest I've gotten so far.

[NobodyXu]

Hello @rvolosatovs we need more information to solve this.

[NobodyXu]

Interested to see how this even worked before. Is the problem xcrun or a shim isn't available on your host? cc's old versions ran xcrun as well but it appears your builds avoided that callpath by having SDKROOT set ahead of time.

After checking the build log, I believe it probably doesn't have xrun.

[NobodyXu]

I think this might be a zig issue, so it should not block the new release of cc.

[rvolosatovs]

I've set CARGO_LOG=trace, you can see the full (failing) build log with 1.0.85 here:
https://github.com/bytecodealliance/wit-deps/actions/runs/7938238802/job/21676790358

For comparison, this is the same build, that succeeds with 1.0.83:
https://github.com/bytecodealliance/wit-deps/actions/runs/7938411356/job/21677189567