Repo doesn't compile without CUDA

[freesig]

Could not find a cuda installation
  stack backtrace:
     0: __rustc::rust_begin_unwind
               at /rustc/6b00bc3880198600130e1cf62b8f8a93494488cc/library/std/src/panicking.rs:697:5
     1: core::panicking::panic_fmt
               at /rustc/6b00bc3880198600130e1cf62b8f8a93494488cc/library/core/src/panicking.rs:75:14
     2: find_cuda_helper::include_cuda
     3: build_script_build::main
     4: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
error: failed to run custom build command for `cust v0.3.2`
note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.

Probably a feature flag that is on by default but we can't have this when app devs will want to run this on machines without nvidia

[freesig]

Actually this is happening because I run with --all-features. I do this because you don't want to miss something that is under a feature flag but given that my main dev machine can't run CUDA I might need another way to do this

[freesig]

Odd, seems to compile without --all-features but I still get the error in the build log.

2025-08-15T10:11:09.541641+10:00 ERROR FetchBuildDataError: error: failed to run custom build command for `risc0-sys v1.4.0`
note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.

Caused by:
  process didn't exit successfully: `/Users/freesig/essential/void-reference-impl/target/debug/build/risc0-sys-0d9215927855a43c/build-script-build` (exit status: 1)
  --- stdout
  cargo:cxx_root=/Users/freesig/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/risc0-sys-1.4.0/cxx
  cargo:cuda_root=/Users/freesig/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/risc0-sys-1.4.0/kernels/zkp/cuda
  cargo:rerun-if-env-changed=RISC0_SKIP_BUILD_KERNELS
  cargo:rerun-if-changed=kernels/zkp/cuda/combos.cu
  cargo:rerun-if-changed=kernels/zkp/cuda/eltwise.cu
  cargo:rerun-if-changed=kernels/zkp/cuda/ffi.cu
  cargo:rerun-if-changed=kernels/zkp/cuda/kernels.cu
  cargo:rerun-if-changed=kernels/zkp/cuda/sha.cu
  cargo:rerun-if-changed=kernels/zkp/cuda/supra/api.cu
  cargo:rerun-if-changed=kernels/zkp/cuda/supra/ntt.cu
  cargo:rerun-if-changed=kernels/zkp/cuda
  cargo:rerun-if-changed=kernels/zkp/cuda/supra
  cargo:rerun-if-env-changed=NVCC_APPEND_FLAGS
  cargo:rerun-if-env-changed=NVCC_PREPEND_FLAGS
  cargo:rerun-if-env-changed=RISC0_CUDART_LINKAGE
  cargo:rerun-if-env-changed=NVCC_CCBIN
  cargo:rerun-if-changed=/Users/freesig/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/risc0-sys-1.4.0/cxx
  cargo:rerun-if-changed=/Users/freesig/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/sppark-0.1.12/sppark
  OUT_DIR = Some(/Users/freesig/essential/void-reference-impl/target/debug/build/risc0-sys-25ea9f55fed4dc48/out)
  OPT_LEVEL = Some(0)
  TARGET = Some(aarch64-apple-darwin)
  HOST = Some(aarch64-apple-darwin)
  cargo:rerun-if-env-changed=CXX_aarch64-apple-darwin
  CXX_aarch64-apple-darwin = None
  cargo:rerun-if-env-changed=CXX_aarch64_apple_darwin
  CXX_aarch64_apple_darwin = None
  cargo:rerun-if-env-changed=HOST_CXX
  HOST_CXX = None
  cargo:rerun-if-env-changed=CXX
  CXX = None
  cargo:rerun-if-env-changed=CC_ENABLE_DEBUG_OUTPUT
  RUSTC_WRAPPER = Some(/Users/freesig/.vscode/extensions/rust-lang.rust-analyzer-0.3.2577-darwin-arm64/server/rust-analyzer)
  cargo:rerun-if-env-changed=NVCC_aarch64-apple-darwin
  NVCC_aarch64-apple-darwin = None
  cargo:rerun-if-env-changed=NVCC_aarch64_apple_darwin
  NVCC_aarch64_apple_darwin = None
  cargo:rerun-if-env-changed=HOST_NVCC
  HOST_NVCC = None
  cargo:rerun-if-env-changed=NVCC
  NVCC = None
  cargo:warning=Compiler family detection failed due to error: ToolNotFound: failed to find tool "nvcc": No such file or directory (os error 2)
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  cargo:rerun-if-env-changed=MACOSX_DEPLOYMENT_TARGET
  MACOSX_DEPLOYMENT_TARGET = None
  cargo:rerun-if-env-changed=CXXFLAGS
  CXXFLAGS = None
  cargo:rerun-if-env-changed=HOST_CXXFLAGS
  HOST_CXXFLAGS = None
  cargo:rerun-if-env-changed=CXXFLAGS_aarch64_apple_darwin
  CXXFLAGS_aarch64_apple_darwin = None
  cargo:rerun-if-env-changed=CXXFLAGS_aarch64-apple-darwin
  CXXFLAGS_aarch64-apple-darwin = None
  CARGO_ENCODED_RUSTFLAGS = Some()

  --- stderr


  error occurred in cc-rs: failed to find tool "nvcc": No such file or directory (os error 2)


error: failed to run custom build command for `cust_raw v0.11.3`
note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.

Caused by:
  process didn't exit successfully: `/Users/freesig/essential/void-reference-impl/target/debug/build/cust_raw-6e2e13c2016863d8/build-script-build` (exit status: 101)
  --- stderr

  thread 'main' panicked at /Users/freesig/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/find_cuda_helper-0.2.0/src/lib.rs:12:13:
  Could not find a cuda installation
  stack backtrace:
     0: __rustc::rust_begin_unwind
               at /rustc/6b00bc3880198600130e1cf62b8f8a93494488cc/library/std/src/panicking.rs:697:5
     1: core::panicking::panic_fmt
               at /rustc/6b00bc3880198600130e1cf62b8f8a93494488cc/library/core/src/panicking.rs:75:14
     2: find_cuda_helper::include_cuda
     3: build_script_build::main
     4: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
error: failed to run custom build command for `cust v0.3.2`
note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.

Caused by:
  process didn't exit successfully: `/Users/freesig/essential/void-reference-impl/target/debug/build/cust-867b7d4d6c17af42/build-script-build` (exit status: 101)
  --- stderr

  thread 'main' panicked at /Users/freesig/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/find_cuda_helper-0.2.0/src/lib.rs:12:13:
  Could not find a cuda installation
  stack backtrace:
     0: __rustc::rust_begin_unwind
               at /rustc/6b00bc3880198600130e1cf62b8f8a93494488cc/library/std/src/panicking.rs:697:5
     1: core::panicking::panic_fmt
               at /rustc/6b00bc3880198600130e1cf62b8f8a93494488cc/library/core/src/panicking.rs:75:14
     2: find_cuda_helper::include_cuda
     3: build_script_build::main
     4: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Running cargo check on the command line doesn't seem to produce errors but I'm wondering if it's just skipping the crates that can't build

[pixelcircuits]

My guess is that it's the checked in Cargo.lock. It should probably not be checked in