cannot run example spec

When I run mdsh on the supplied spec files from the README I get errors. ## Reproduce ``` $ nix run github:NixOS/nixpkgs/e57b3b16ad8758fd681511a078f35c416a8cc939#mdsh -- -i spec.clear.md ``` (I used the latest nixpkgs unstable version because this repo's master doesn't build for me locally) ## What I expected Successful exit, spec.processed.md and spec.clear.md to be equal ## Observed ``` $ nix run nixpkgs/nixpkgs-unstable#mdsh -- -i spec.clear.md Using input=File("spec.clear.md") output=File("spec.clear.md") work_dir=Parent("/Users/user/tmp/mdsh") clean=false frozen=false `> $ echo 'I am *markdown*'` `> < ./samples/example.md` `> yaml $ echo 'foo: true'` `> yaml < ./samples/example.yml` `> yaml foo: true` `! $ echo 'foo=bar'` thread 'main' panicked at src/main.rs:419:25: WTF, not supported note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace $ echo $? 101 ``` ## System ``` $ nix-info -m - system: `"aarch64-darwin"` - host os: `Darwin 24.6.0, macOS 15.6.1` - multi-user?: `yes` - sandbox: `no` - version: `nix-env (Nix) 2.28.3` - nixpkgs: `/nix/store/x06djk7jw02qb6y8fxd0mjgaksw2kd9n-source` ```