Build error ...the option 'allow-import-from-derivation' is disabled

[mhwombat]

This is my first time using FlakeHub to publish one of my flakes. The flake itself works fine; I don't know why this error is happening.

Error

Error: 
   0: Checking flake evaluates
   1: Failed to execute command `nix flake show --all-systems --json --no-write-lock-file /home/runner/work/pandoc-select-code/pandoc-select-code/` with status 1 
      stdout: 
      stderr: 
[K
[Kevaluating ''...
      copying path '/nix/store/88fpp9lrbs0vk8yf94bz045y3bfz7m2r-source' from 'https://cache.nixos.org'...
      error:
             … while evaluating the attribute 'optionalValue.value'

               at /nix/store/khkbz6l5c4l6iz6775003sl19l6s2vrl-source/lib/modules.nix:799:5:

                798|
                799|     optionalValue =
                   |     ^
                800|       if isDefined then { value = mergedValue; }

             … while evaluating a branch condition

               at /nix/store/khkbz6l5c4l6iz6775003sl19l6s2vrl-source/lib/modules.nix:800:7:

                799|     optionalValue =
                800|       if isDefined then { value = mergedValue; }
                   |       ^
                801|       else {};

             (stack trace truncated; use '--show-trace' to show the full trace)

             error: cannot build '/nix/store/9b5sj9s8mlk33x036hbs934cwjd8pdrc-cabal2nix-pandoc-select-code.drv^out' during evaluation because the option 'allow-import-from-derivation' is disabled

Metadata

key	value
version	0.1.0
os	linux
arch	x86_64

SpanTrace

SpanTrace:
   0: flakehub_push::flake_info::check_flake_evaluates
           with directory=/home/runner/work/pandoc-select-code/pandoc-select-code/
             at src/flake_info.rs:54
   1: flakehub_push::cli::push_new_release
           with repository=mhwombat/pandoc-select-code mirror=false upload_name=mhwombat/pandoc-logic-proof
             at src/cli/mod.rs:472
   2: flakehub_push::cli::flakehub_push
             at src/cli/mod.rs:257

[mhwombat]

It is a Haskell project, so I suspect I'm getting bitten by Issue #69 .