Hi, I’ve read @Gabriel439’s post Haskell for all: Nixpkgs support for Linux builders running on macOS and Nixpkgs Reference Manual and it seems very exciting. I’m hoping to automate building some nixos vms for people on my team both on mac and linux, and this seems a great way to get it working for everyone.
My understanding is that I should be able to run nix run nixpkgs#darwin.builder and it should launch a linux nixos vm for building using qemu all in one step.
This requires macOS version 12.4 or later.
I’m on 13.4
You will also need to be a trusted user for your Nix installation
I have the extra-trusted-users set up.
But after creating the ssh keys (first run only), it breaks:
❯ nix run nixpkgs#darwin.builder
Disk image do not exist, creating the virtualisation disk image...
Formatting '/tmp/tmp.PlKPnRQYvj', fmt=raw size=21474836480
/nix/store/4mx7h23lbrf1csjmnf5fcd9nvzgrya2n-nixos-vm/bin/run-nixos-vm: line 14: /nix/store/sh0plpi3ddar4g7ws7ww37r5kv0rg51j-e2fsprogs-1.47.0-bin/bin/mkfs.ext4: cannot execute binary file: Exec format error
appears like the run-nixos-vm script is trying to run linux binary
❯ file /nix/store/sh0plpi3ddar4g7ws7ww37r5kv0rg51j-e2fsprogs-1.47.0-bin/bin/mkfs.ext4
/nix/store/sh0plpi3ddar4g7ws7ww37r5kv0rg51j-e2fsprogs-1.47.0-bin/bin/mkfs.ext4: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /nix/store/n8hgw8lja68x3zhv2ww9a7b6npbkvh21-glibc-2.37-8/lib/ld-linux-aarch64.so.1, for GNU/Linux 3.10.0, not stripped
The failing part of the script /nix/store/4mx7h23lbrf1csjmnf5fcd9nvzgrya2n-nixos-vm/bin/run-nixos-vm is
7 │ # Create an empty ext4 filesystem image. A filesystem image does not
8 │ # contain a partition table but just a filesystem.
9 │ createEmptyFilesystemImage() {
10 │ local name=$1
11 │ local size=$2
12 │ local temp=$(mktemp)
13 │ /nix/store/lyr3h4mi8nqhbk6gz08k6rq6wnq8rpy9-qemu-host-cpu-only-8.0.2/bin/qemu-img create -f raw "$temp" "$size"
14 │ /nix/store/sh0plpi3ddar4g7ws7ww37r5kv0rg51j-e2fsprogs-1.47.0-bin/bin/mkfs.ext4 -L nixos "$temp"
15 │ /nix/store/lyr3h4mi8nqhbk6gz08k6rq6wnq8rpy9-qemu-host-cpu-only-8.0.2/bin/qemu-img convert -f raw -O qcow2 "$temp" "$name"
16 │ rm "$temp"
17 │ }
And the other binaries being executed there look to be the correct format, just mkfs.ext4 is the linux one somehow.
❯ file /nix/store/lyr3h4mi8nqhbk6gz08k6rq6wnq8rpy9-qemu-host-cpu-only-8.0.2/bin/qemu-img
/nix/store/lyr3h4mi8nqhbk6gz08k6rq6wnq8rpy9-qemu-host-cpu-only-8.0.2/bin/qemu-img: Mach-O 64-bit executable arm64
❯ file /nix/store/sh0plpi3ddar4g7ws7ww37r5kv0rg51j-e2fsprogs-1.47.0-bin/bin/mkfs.ext4
/nix/store/sh0plpi3ddar4g7ws7ww37r5kv0rg51j-e2fsprogs-1.47.0-bin/bin/mkfs.ext4: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /nix/store/n8hgw8lja68x3zhv2ww9a7b6npbkvh21-glibc-2.37-8/lib/ld-linux-aarch64.so.1, for GNU/Linux 3.10.0, not stripped
❯ file /nix/store/lyr3h4mi8nqhbk6gz08k6rq6wnq8rpy9-qemu-host-cpu-only-8.0.2/bin/qemu-img
/nix/store/lyr3h4mi8nqhbk6gz08k6rq6wnq8rpy9-qemu-host-cpu-only-8.0.2/bin/qemu-img: Mach-O 64-bit executable arm64
Is this a regression maybe in nixpkgs-unstable, or could there be something wrong with my system? I’m not sure where to start debugging.