clang not installed

[luca992]

On my M1 Mac (if that matters) optimizing https://github.com/baedrik/snip721-reference-impl fails with the following error:

error: failed to run custom build command for `secp256k1-sys v0.8.1`

Caused by:
  process didn't exit successfully: `/target/release/build/secp256k1-sys-e2b44dbcca8fd742/build-script-build` (exit status: 1)
  --- stdout
  TARGET = Some("wasm32-unknown-unknown")
  OPT_LEVEL = Some("3")
  HOST = Some("aarch64-unknown-linux-musl")
  cargo:rerun-if-env-changed=CC_wasm32-unknown-unknown
  CC_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CC_wasm32_unknown_unknown
  CC_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CC
  TARGET_CC = None
  cargo:rerun-if-env-changed=CC
  CC = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32-unknown-unknown
  CFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32_unknown_unknown
  CFLAGS_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CFLAGS
  TARGET_CFLAGS = None
  cargo:rerun-if-env-changed=CFLAGS
  CFLAGS = None
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("false")
  cargo:rerun-if-env-changed=CC_wasm32-unknown-unknown
  CC_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CC_wasm32_unknown_unknown
  CC_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CC
  TARGET_CC = None
  cargo:rerun-if-env-changed=CC
  CC = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32-unknown-unknown
  CFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32_unknown_unknown
  CFLAGS_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CFLAGS
  TARGET_CFLAGS = None
  cargo:rerun-if-env-changed=CFLAGS
  CFLAGS = None
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  running: "clang" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "--target=wasm32-unknown-unknown" "-I" "depend/secp256k1/" "-I" "depend/secp256k1/include" "-I" "depend/secp256k1/src" "-I" "wasm/wasm-sysroot" "-Wall" "-Wextra" "-DSECP256K1_API=" "-DENABLE_MODULE_ECDH=1" "-DENABLE_MODULE_SCHNORRSIG=1" "-DENABLE_MODULE_EXTRAKEYS=1" "-DECMULT_GEN_PREC_BITS=4" "-DECMULT_WINDOW_SIZE=15" "-DUSE_EXTERNAL_DEFAULT_CALLBACKS=1" "-o" "/target/wasm32-unknown-unknown/release/build/secp256k1-sys-7ea7f846d3a102ce/out/wasm/wasm.o" "-c" "wasm/wasm.c"
  cargo:rerun-if-env-changed=CC_wasm32-unknown-unknown
  CC_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CC_wasm32_unknown_unknown
  CC_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CC
  TARGET_CC = None
  cargo:rerun-if-env-changed=CC
  CC = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32-unknown-unknown
  CFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CFLAGS_wasm32_unknown_unknown
  CFLAGS_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CFLAGS
  TARGET_CFLAGS = None
  cargo:rerun-if-env-changed=CFLAGS
  CFLAGS = None
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  running: "clang" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "--target=wasm32-unknown-unknown" "-I" "depend/secp256k1/" "-I" "depend/secp256k1/include" "-I" "depend/secp256k1/src" "-I" "wasm/wasm-sysroot" "-I" "wasm/wasm-sysroot" "-Wall" "-Wextra" "-DSECP256K1_API=" "-DENABLE_MODULE_ECDH=1" "-DENABLE_MODULE_SCHNORRSIG=1" "-DENABLE_MODULE_EXTRAKEYS=1" "-DECMULT_GEN_PREC_BITS=4" "-DECMULT_WINDOW_SIZE=15" "-DUSE_EXTERNAL_DEFAULT_CALLBACKS=1" "-o" "/target/wasm32-unknown-unknown/release/build/secp256k1-sys-7ea7f846d3a102ce/out/wasm/wasm.o" "-c" "wasm/wasm.c"

  --- stderr


  error occurred: Failed to find tool. Is `clang` installed?

[webmaster128]

C-based crates like secp256k1-sys are not really supported in the CowmWasm ecosystem. You may get this to work with a lot of effort but I would not rely on it. There are nice pure-Rust secp256k1 implementations you can compile to Wasm much easier.

[luca992]

C-based crates like secp256k1-sys are not really supported in the CowmWasm ecosystem. You may get this to work with a lot of effort but I would not rely on it. There are nice pure-Rust secp256k1 implementations you can compile to Wasm much easier.

It's due to secret-toolkit-crypto having a dependency on secp256k1 which depends on secp256k1-sys.
Eitherway, the much simpler secret-contract-optimizer handles it just fine.

[luca992]

I meant why can't this docker work as well?

[webmaster128]

Because right now supporting a build system for other languages than Rust is not a priority. The C dependency is an unnecessary source of pain when you can just use a Rust dependency.