hash '' has wrong length for hash type 'md5'

[jtojnar]

Describe the bug

I am trying to build python3.pkgs.libevdev from NixOS/nixpkgs#92715 on aarch64 community box by running nix-build -A python3.pkgs.libevdev --argstr system aarch64-linux but it fails:

these derivations will be built:
  /nix/store/q701iz58annc5swl5v9w5gjbwbcjgkkl-fix-paths.patch.drv
  /nix/store/jamh4v46nbmk40ak1643xxczdx0hxkjk-python3.8-libevdev-0.9.drv
these paths will be fetched (43.20 MiB download, 219.85 MiB unpacked):
  /nix/store/1w51j2y63wvpcy04grgaf5axva13qdpa-pip-install-hook
  /nix/store/3mh2mdnh38f6argfplwjz48477qhvb03-python3.8-py-1.8.1
  /nix/store/4jq0pdh3nn4228amaaq1w054xdns856m-setuptools-check-hook
  /nix/store/4qvamlvbqn2vd2qa26bky72726vgyd07-python3.8-setuptools-46.1.3
  /nix/store/5dkkjjhq0gdiwl8a2b1i5w5zjjw8jw6j-python3.8-packaging-20.4
  /nix/store/7i2ry8cj3c5lgyazmhnk70s1j16fwins-python-recompile-bytecode-hook
  /nix/store/7w8p324gd26vpkcs78qjk3mdjpldjjmh-python3.8-zipp-3.1.0
  /nix/store/8ac15d2gfyz8vfazl28d5p8z9k98npqj-python3.8-wheel-0.33.6
  /nix/store/8mzhhh6ib8ydmf6b1cl1w7l1ppydgl1q-binutils-2.31.1
  /nix/store/8n3f4f3dhdcp0hi7yqiinwsy2a289r5j-gcc-wrapper-9.3.0
  /nix/store/8nhjqwdd5b1f7zmm37a4fmb8b7nx5r5r-python-catch-conflicts-hook
  /nix/store/akivgaqxccl21r2wck29d8s9zh6i572q-binutils-wrapper-2.31.1
  /nix/store/cfjj10lx6bk7w2qrfbwljrfkqjqqn310-python3.8-pyparsing-2.4.6
  /nix/store/cigmvyr1cnvkaz91i4i29jbi1wlzzbls-python3.8-pip-20.1.1
  /nix/store/cngwjyxw63sblwkpk94j309n8wny29aq-pytest-check-hook
  /nix/store/gyydp378c5sxijhchdvl2kkn2x4vvc82-hook
  /nix/store/i4nfqm06fq366q634gzmi6al5p9czq5y-python3.8-six-1.15.0
  /nix/store/mrplxkbwmxwmf5kq201paxv27hyx2ff7-setuptools-setup-hook
  /nix/store/mzc0v098i0i0zylp3i0fnjk38kxsz48x-python3.8-pluggy-0.13.1
  /nix/store/nwfisv57z29dak533dhrbnxwj5ggnnjm-stdenv-linux
  /nix/store/padhfcd4ijwry3lnddfi1rp4649cb7wg-python3.8-attrs-19.3.0
  /nix/store/q8hgkcm6giww7r9lbfl5sf12ykv57sgy-python3-3.8.3
  /nix/store/qds92qssvzs5x2gdg3gika51whvq2fjk-python3.8-importlib-metadata-1.6.0
  /nix/store/qrgyjiaxxjmmn15051jxxj7wkkj0y01v-python-imports-check-hook.sh
  /nix/store/s6zhjxwinnw6liz6kqwdyiv6cf2m3ax6-sqlite-3.32.2
  /nix/store/vrr4fx5z16jxnmwm6hzj4wdp1cqqha6z-python3.8-pytest-5.4.3
  /nix/store/wbb1vlxzap2ih25q2gmxxs5nniny1myl-python3.8-more-itertools-8.3.0
  /nix/store/xgh4vpggyhjlfafjn31j2s38vwwkpprd-python3.8-wcwidth-0.2.3
  /nix/store/ywf0kxg9x89jxg40riv40nxfr5by350r-python3.8-atomicwrites-1.4.0
  /nix/store/zzrvbbq37l6ykksqrj7n0pxcr2g6hj5q-gcc-9.3.0
building '/nix/store/q701iz58annc5swl5v9w5gjbwbcjgkkl-fix-paths.patch.drv' on 'ssh://jtojnar@aarch64.nixos.community'...
copying path '/nix/store/s6zhjxwinnw6liz6kqwdyiv6cf2m3ax6-sqlite-3.32.2' from 'https://cache.nixos.org'...
copying path '/nix/store/zzrvbbq37l6ykksqrj7n0pxcr2g6hj5q-gcc-9.3.0' from 'https://cache.nixos.org'...
copying path '/nix/store/8mzhhh6ib8ydmf6b1cl1w7l1ppydgl1q-binutils-2.31.1' from 'https://cache.nixos.org'...
copying 1 paths...
copying path '/nix/store/f75n3yqnbj5ji3qlx6j9d58fzbg22fss-fix-paths.patch' to 'ssh://jtojnar@aarch64.nixos.community'...
error: --- Error --- nix-store
error: --- BadHash --- nix-daemon
hash '' has wrong length for hash type 'md5'
error: --- EndOfFile --- build-remote
unexpected end-of-file
error: --- Error --- nix-daemon
builder for '/nix/store/q701iz58annc5swl5v9w5gjbwbcjgkkl-fix-paths.patch.drv' failed with exit code 1; last 3 log lines:
  error: --- Error --- nix-store
  error: --- BadHash --- nix-daemon
  hash '' has wrong length for hash type 'md5'
error: --- Error --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- nix-build
got unknown message type 1 from Nix daemon

Steps To Reproduce

1. Create test.nix with the following contents in your nixpkgs tree:

{ system ? builtins.currentSystem, pkgs ? import ./. { inherit system; } }:
pkgs.runCommand "test" {
  foo = ./test.nix;
} ''
  cp $foo $out
''

2. Configure your system to use nix-community aarch64 builder
3. Run nix-build test.nix --argstr system aarch64-linux
4. See error

these derivations will be built:
  /nix/store/cld1lxvy0axs1ags3g6i1a418a4p8w8w-test.drv
building '/nix/store/cld1lxvy0axs1ags3g6i1a418a4p8w8w-test.drv' on 'ssh://jtojnar@aarch64.nixos.community'...
copying 1 paths...
copying path '/nix/store/gm6k4xha2x93376amsa192nf2dkm536p-test.nix' to 'ssh://jtojnar@aarch64.nixos.community'...
error: --- Error --- nix-store
error: --- BadHash --- nix-daemon
hash '' has wrong length for hash type 'md5'
error: --- EndOfFile --- build-remote
unexpected end-of-file
error: --- Error --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- nix-build
error: --- Error --- nix-daemon
builder for '/nix/store/cld1lxvy0axs1ags3g6i1a418a4p8w8w-test.drv' failed with exit code 1; last 3 log lines:
  error: --- Error --- nix-store
  error: --- BadHash --- nix-daemon
  hash '' has wrong length for hash type 'md5'

Expected behavior

Build should succeed.

nix-env --version output

nix-env (Nix) 2.4pre20200622_334e26b

Additional context

Both derivations look pretty much the same:

$ cat /nix/store/qa79a9prdsknkc2bqlajmwws1ywacaql-fix-paths.patch.drv
Derive([("out","/nix/store/qndmc7phnipz0y14gyhv2kb6fc0lap83-fix-paths.patch","","")],[("/nix/store/2zjdbksfsb4xlqhq45vd1j1hifq3npnd-bash-4.4-p23.drv",["out"]),("/nix/store/n106hva3clw48b7qv5ll7asryn74l6hq-libevdev-1.9.0.drv",["out"]),("/nix/store/yr14ipdfc7hg5a6avd6m0lqx519vwxda-stdenv-linux.drv",["out"])],["/nix/store/4vq3350zc6sqnibkqpgic2d6cvi1r9hq-substitute-all.sh","/nix/store/f75n3yqnbj5ji3qlx6j9d58fzbg22fss-fix-paths.patch"],"x86_64-linux","/nix/store/ypag3bh7y7i15xf24zihr343wi6x5i6g-bash-4.4-p23/bin/bash",["-e","/nix/store/4vq3350zc6sqnibkqpgic2d6cvi1r9hq-substitute-all.sh"],[("allowSubstitutes",""),("buildInputs",""),("builder","/nix/store/ypag3bh7y7i15xf24zihr343wi6x5i6g-bash-4.4-p23/bin/bash"),("configureFlags",""),("depsBuildBuild",""),("depsBuildBuildPropagated",""),("depsBuildTarget",""),("depsBuildTargetPropagated",""),("depsHostHost",""),("depsHostHostPropagated",""),("depsTargetTarget",""),("depsTargetTargetPropagated",""),("doCheck",""),("doInstallCheck",""),("libevdev","/nix/store/23pqn2pj71j4pxyva3hkkqvp7cc71ymv-libevdev-1.9.0"),("name","fix-paths.patch"),("nativeBuildInputs",""),("out","/nix/store/qndmc7phnipz0y14gyhv2kb6fc0lap83-fix-paths.patch"),("outputs","out"),("patches",""),("preferLocalBuild","1"),("propagatedBuildInputs",""),("propagatedNativeBuildInputs",""),("src","/nix/store/f75n3yqnbj5ji3qlx6j9d58fzbg22fss-fix-paths.patch"),("stdenv","/nix/store/xrzmin0q0jrq3xavfxivwm0jf8znhi5a-stdenv-linux"),("strictDeps",""),("system","x86_64-linux")])⏎                                                                                                                                                                                                 $ cat /nix/store/q701iz58annc5swl5v9w5gjbwbcjgkkl-fix-paths.patch.drv
Derive([("out","/nix/store/wdsd8qkp0vfadln31f6x6l9fbsxc6rc4-fix-paths.patch","","")],[("/nix/store/7asxfvqs40ywpkf43bv0f9s66zdhi0a9-stdenv-linux.drv",["out"]),("/nix/store/9b58n0rf3i1la65aiizvb5d1fn3ydwz1-bash-4.4-p23.drv",["out"]),("/nix/store/f0jll9w3y631ng280irlcyfffsa8liwf-libevdev-1.9.0.drv",["out"])],["/nix/store/4vq3350zc6sqnibkqpgic2d6cvi1r9hq-substitute-all.sh","/nix/store/f75n3yqnbj5ji3qlx6j9d58fzbg22fss-fix-paths.patch"],"aarch64-linux","/nix/store/v2fg7mzwayjrkvbnhf766881zmf5afsv-bash-4.4-p23/bin/bash",["-e","/nix/store/4vq3350zc6sqnibkqpgic2d6cvi1r9hq-substitute-all.sh"],[("allowSubstitutes",""),("buildInputs",""),("builder","/nix/store/v2fg7mzwayjrkvbnhf766881zmf5afsv-bash-4.4-p23/bin/bash"),("configureFlags",""),("depsBuildBuild",""),("depsBuildBuildPropagated",""),("depsBuildTarget",""),("depsBuildTargetPropagated",""),("depsHostHost",""),("depsHostHostPropagated",""),("depsTargetTarget",""),("depsTargetTargetPropagated",""),("doCheck",""),("doInstallCheck",""),("libevdev","/nix/store/anawrr4rm8njbbf3w56bjgmw9d4jf2xs-libevdev-1.9.0"),("name","fix-paths.patch"),("nativeBuildInputs",""),("out","/nix/store/wdsd8qkp0vfadln31f6x6l9fbsxc6rc4-fix-paths.patch"),("outputs","out"),("patches",""),("preferLocalBuild","1"),("propagatedBuildInputs",""),("propagatedNativeBuildInputs",""),("src","/nix/store/f75n3yqnbj5ji3qlx6j9d58fzbg22fss-fix-paths.patch"),("stdenv","/nix/store/cnpd9k9sh5001q01zqrrrlci8wpkb64d-stdenv-linux"),("strictDeps",""),("system","aarch64-linux")])⏎                                                                                                                                                                                               

I have the remote builder configured as suggested in the community box README:

{
  nix = {
    distributedBuilds = true;
    buildMachines = [
      {
        hostName = "aarch64.nixos.community";
        maxJobs = 64;
        sshKey = "/root/id_aarch64box";
        sshUser = "jtojnar";
        system = "aarch64-linux";
        supportedFeatures = [ "big-parallel" ];
      }
    ];
  };
}

[colemickens]

This is severely impacting my ability to use Nix, for example, for mobile-nixos I am almost completely blocked right now.

I had been getting around this by copying the drvs to the builder, but this doesn't work well in all scenarios.

[stale]

I marked this as stale due to inactivity. → More info