Docker can't find build.toml

[kamakuta]

I'm trying to run docker run --mount type=bind,source=$(pwd),target=/kernelcode ghcr.io/huggingface/kernel-builder:{SHA} from the README's Quick Start, but it crashes with Error: Cannot open build.toml for reading.

Steps to reproduce:

git clone https://github.com/huggingface/kernel-builder
cd kernel-builder/examples/activation/
docker run --mount type=bind,source=$(pwd),target=/kernelcode ghcr.io/huggingface/kernel-builder:latest

I get

Building Torch Extension Bundle
Building with rev vgy6yxyszg
No flake.nix found, creating a basic one...
flake.nix created. You can customize it as needed.
this derivation will be built:
  /nix/store/gccmdrfhspids0gybs3191i1n16q33cj-update-build.drv
these 37 paths will be fetched (18.18 MiB download, 84.78 MiB unpacked):
  /nix/store/z8fzi165wkivbikld909bl5zk6r29vsx-acl-2.3.2
  /nix/store/49dxdr3ln7xfna1b94vi5hra6rgqk6h1-attr-2.5.2
  /nix/store/xg75pc4yyfd5n2fimhb98ps910q5lm5n-bash-5.2p37
  /nix/store/dknmf3dcqcag8g2wy0f5a6bhscqwi3r5-build2cmake-0.2.1
  /nix/store/mq1680dppidpggmaqaklwapvgm6iw3a6-bzip2-1.0.8
  /nix/store/sysih19x8xx8l473d3qnr760hy758lkq-bzip2-1.0.8-bin
  /nix/store/cg09nslw3w6afyynjw484b86d47ic1cb-coreutils-9.7
  /nix/store/8cs5vjkbwf2vicgms4km5k1kgbznhwip-diffutils-3.12
  /nix/store/f2dlmh055sqy5xqk0qrswfvpddxgy9hz-ed-1.21.1
  /nix/store/hb9v0qx9vk0420z5grlnv2y5wcf6dp6i-file-5.46
  /nix/store/frspb25x6v43fwv6b0wna1fm5nsqcp0b-findutils-4.10.0
  /nix/store/f8x04xqd2cs274k0hgfzsrms6sby2fgx-gawk-5.3.2
  /nix/store/gv7z0km39q3fgzavpic8vrl7smh5n2w6-gcc-14.2.1.20250322-lib
  /nix/store/0x600292yi5qzg389nan9j4dvzlh8785-gcc-14.2.1.20250322-libgcc
  /nix/store/g3s0z9r7m1lsfxdk8bj88nw8k8q3dmmg-glibc-2.40-66
  /nix/store/g0i57kz7yrssdv4iw2bj8202xxpl8dbq-gmp-with-cxx-6.3.0
  /nix/store/dhiwbm7kzlc01yk99900g8lj2g7faxyn-gnu-config-2024-01-01
  /nix/store/2wni3gbcf6fqwlfb2h9sv7jvqlpf1ylq-gnugrep-3.11
  /nix/store/agn71jakv0a9669k3zx5g9aqm2sl9z77-gnumake-4.4.1
  /nix/store/1h8gf327cgid0jgjygrj31amp63mn7a7-gnused-4.9
  /nix/store/5jmcn57x2j9mkdr3j947cbja2hpxmhfn-gnutar-1.35
  /nix/store/04z4rhjadrnd0w3ib2sl42pa3xjgpf7p-gzip-1.14
  /nix/store/cjs7mgw6q8zp75qapfmqhqnbf62b3fwa-libgit2-1.9.0-lib
  /nix/store/y0ii7yfaxi2k2vnfyknb64rcczsdyjkf-libidn2-2.3.8
  /nix/store/1i5cz1bqy7g9kaq6dkaqchn857b2h8cs-libssh2-1.11.1
  /nix/store/vzdd455zm255kx85hg1cvci3bbn8adwj-libunistring-1.3
  /nix/store/8ms1zkkidmvnghnvdx07yjzj8cvi4dzm-llhttp-9.2.1
  /nix/store/xy8x4g472i5n1bh24c5ixhbnk6qlm9vz-openssl-3.4.1
  /nix/store/qd20g193gch8bj4h0h44wr97mw0bhkmf-patch-2.7.6
  /nix/store/5yl5rscbbqh9b3r9ixi6cnzfaydq9n9r-patchelf-0.15.0
  /nix/store/chg330wi4p9g0r9bab2186wwhbgmlm5z-pcre2-10.44
  /nix/store/lgydi1gl5wqcw6k4gyjbaxx7b40zxrsp-stdenv-linux
  /nix/store/d41c6ccm4yaq2czglxs10lzkynrmd399-update-autotools-gnu-config-scripts-hook
  /nix/store/fdsndp18qa1fk375vcd4vrn00c0p4zpr-xgcc-14.2.1.20250322-libgcc
  /nix/store/hzfjla4v6x1851jh0wakajlqif0jxrgy-xz-5.8.1
  /nix/store/fi495i6cz40rq1axig930jzyw7ln0zhm-xz-5.8.1-bin
  /nix/store/8dr41ckl7sbv2v5aim3csxzql03z68hk-zlib-1.3.1
copying path '/nix/store/0x600292yi5qzg389nan9j4dvzlh8785-gcc-14.2.1.20250322-libgcc' from 'https://cache.nixos.org'...
copying path '/nix/store/dhiwbm7kzlc01yk99900g8lj2g7faxyn-gnu-config-2024-01-01' from 'https://cache.nixos.org'...
copying path '/nix/store/fdsndp18qa1fk375vcd4vrn00c0p4zpr-xgcc-14.2.1.20250322-libgcc' from 'https://cache.nixos.org'...
copying path '/nix/store/vzdd455zm255kx85hg1cvci3bbn8adwj-libunistring-1.3' from 'https://cache.nixos.org'...
copying path '/nix/store/d41c6ccm4yaq2czglxs10lzkynrmd399-update-autotools-gnu-config-scripts-hook' from 'https://cache.nixos.org'...
copying path '/nix/store/y0ii7yfaxi2k2vnfyknb64rcczsdyjkf-libidn2-2.3.8' from 'https://cache.nixos.org'...
copying path '/nix/store/g3s0z9r7m1lsfxdk8bj88nw8k8q3dmmg-glibc-2.40-66' from 'https://cache.nixos.org'...
copying path '/nix/store/49dxdr3ln7xfna1b94vi5hra6rgqk6h1-attr-2.5.2' from 'https://cache.nixos.org'...
copying path '/nix/store/xg75pc4yyfd5n2fimhb98ps910q5lm5n-bash-5.2p37' from 'https://cache.nixos.org'...
copying path '/nix/store/mq1680dppidpggmaqaklwapvgm6iw3a6-bzip2-1.0.8' from 'https://cache.nixos.org'...
copying path '/nix/store/f2dlmh055sqy5xqk0qrswfvpddxgy9hz-ed-1.21.1' from 'https://cache.nixos.org'...
copying path '/nix/store/f8x04xqd2cs274k0hgfzsrms6sby2fgx-gawk-5.3.2' from 'https://cache.nixos.org'...
copying path '/nix/store/gv7z0km39q3fgzavpic8vrl7smh5n2w6-gcc-14.2.1.20250322-lib' from 'https://cache.nixos.org'...
copying path '/nix/store/agn71jakv0a9669k3zx5g9aqm2sl9z77-gnumake-4.4.1' from 'https://cache.nixos.org'...
copying path '/nix/store/1h8gf327cgid0jgjygrj31amp63mn7a7-gnused-4.9' from 'https://cache.nixos.org'...
copying path '/nix/store/8ms1zkkidmvnghnvdx07yjzj8cvi4dzm-llhttp-9.2.1' from 'https://cache.nixos.org'...
copying path '/nix/store/xy8x4g472i5n1bh24c5ixhbnk6qlm9vz-openssl-3.4.1' from 'https://cache.nixos.org'...
copying path '/nix/store/chg330wi4p9g0r9bab2186wwhbgmlm5z-pcre2-10.44' from 'https://cache.nixos.org'...
copying path '/nix/store/hzfjla4v6x1851jh0wakajlqif0jxrgy-xz-5.8.1' from 'https://cache.nixos.org'...
copying path '/nix/store/8dr41ckl7sbv2v5aim3csxzql03z68hk-zlib-1.3.1' from 'https://cache.nixos.org'...
copying path '/nix/store/z8fzi165wkivbikld909bl5zk6r29vsx-acl-2.3.2' from 'https://cache.nixos.org'...
copying path '/nix/store/sysih19x8xx8l473d3qnr760hy758lkq-bzip2-1.0.8-bin' from 'https://cache.nixos.org'...
copying path '/nix/store/hb9v0qx9vk0420z5grlnv2y5wcf6dp6i-file-5.46' from 'https://cache.nixos.org'...
copying path '/nix/store/qd20g193gch8bj4h0h44wr97mw0bhkmf-patch-2.7.6' from 'https://cache.nixos.org'...
copying path '/nix/store/fi495i6cz40rq1axig930jzyw7ln0zhm-xz-5.8.1-bin' from 'https://cache.nixos.org'...
copying path '/nix/store/2wni3gbcf6fqwlfb2h9sv7jvqlpf1ylq-gnugrep-3.11' from 'https://cache.nixos.org'...
copying path '/nix/store/5jmcn57x2j9mkdr3j947cbja2hpxmhfn-gnutar-1.35' from 'https://cache.nixos.org'...
copying path '/nix/store/04z4rhjadrnd0w3ib2sl42pa3xjgpf7p-gzip-1.14' from 'https://cache.nixos.org'...
copying path '/nix/store/1i5cz1bqy7g9kaq6dkaqchn857b2h8cs-libssh2-1.11.1' from 'https://cache.nixos.org'...
copying path '/nix/store/g0i57kz7yrssdv4iw2bj8202xxpl8dbq-gmp-with-cxx-6.3.0' from 'https://cache.nixos.org'...
copying path '/nix/store/5yl5rscbbqh9b3r9ixi6cnzfaydq9n9r-patchelf-0.15.0' from 'https://cache.nixos.org'...
copying path '/nix/store/cjs7mgw6q8zp75qapfmqhqnbf62b3fwa-libgit2-1.9.0-lib' from 'https://cache.nixos.org'...
copying path '/nix/store/cg09nslw3w6afyynjw484b86d47ic1cb-coreutils-9.7' from 'https://cache.nixos.org'...
copying path '/nix/store/dknmf3dcqcag8g2wy0f5a6bhscqwi3r5-build2cmake-0.2.1' from 'https://huggingface.cachix.org'...
copying path '/nix/store/8cs5vjkbwf2vicgms4km5k1kgbznhwip-diffutils-3.12' from 'https://cache.nixos.org'...
copying path '/nix/store/frspb25x6v43fwv6b0wna1fm5nsqcp0b-findutils-4.10.0' from 'https://cache.nixos.org'...
copying path '/nix/store/lgydi1gl5wqcw6k4gyjbaxx7b40zxrsp-stdenv-linux' from 'https://cache.nixos.org'...
building '/nix/store/gccmdrfhspids0gybs3191i1n16q33cj-update-build.drv'...
Error: Cannot open build.toml for reading

Caused by:
    No such file or directory (os error 2)

Location:
    src/main.rs:241:10

If I run docker interactively, I can read it

docker run -it --mount type=bind,source=$(pwd),target=/kernelcode --entrypoint /bin/sh ghcr.io/huggingface/kernel-builder:latest
sh-5.2$ cat /kernelcode/build.toml
[general]
name = "activation"
universal = false

[torch]
src = [
    "torch-ext/torch_binding.cpp",
    "torch-ext/torch_binding.h",
]

[kernel.activation]
backend = "cuda"
depends = ["torch"]
src = [
    "activation/activation_kernels.cu",
    "activation/cuda_compat.h",
    "activation/dispatch_utils.h",
]

[drbh]

Hi @kamakuta thank you very much for reporting this problem 🙏

I believe there was an issue with the command in the readme as well as a small bug in the dockerfile. I've opened a PR that should resolve these issues here: #166

In the meantime, may I recommend using nix for the build process? We strongly encourage using nix directly (it is used in the docker container) as it has some caching benefits and is a bit more robust.

Building with nix

Once nix is installed the examples can be built via this command:

cd examples/activation
nix build . \
  --override-input kernel-builder github:huggingface/kernel-builder \
  -L

Thanks!