'svelte-kit package' outputs package dir relative to tsconfig, but post-build code searches relative to svelte.config.js

[martaver]

Describe the bug

I'm experimenting with a setup that has sveltekit apps and libs in the same monorepo, in subdirectories. To cater to this, I have a single svelte.config.js that accepts a subdir as argument and adds it to files, vite.cachedir and vite.server.fs.allow.

I noticed that when trying to publish a lib, the svelte-kit package command fails with:

> ENOENT: no such file or directory, scandir '<repo_root>/package'

Searching for the missing package folder, I find it nested under libs/ui, which is surprising, because I haven't set package.dir in svelte.config.js yet.

If I set package.dir to libs/ui/package, then the ERROR now shows the correct path, but the package dir is now doubly nested under libs/ui/libs/ui/package.

Fiddling around, it seems that package.dir emits relative to tsconfig.json, because if I move it around, the relative package dir also moves.

Reproduction

https://github.com/cleric-sh/repro/tree/sveltekit-package-nested-dir

just clone and yarn && yarn svelte-kit package

Logs

No response

System Info

npx: installed 1 in 1.152s

  System:
    OS: macOS 11.2.3
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 2.41 GB / 64.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 14.17.6 - ~/.nvm/versions/node/v14.17.6/bin/node
    Yarn: 1.22.10 - /usr/local/bin/yarn
    npm: 6.14.15 - ~/.nvm/versions/node/v14.17.6/bin/npm
  Browsers:
    Chrome: 96.0.4664.55
    Firefox: 92.0
    Safari: 14.0.3
  npmPackages:
    @sveltejs/adapter-auto: next => 1.0.0-next.3 
    @sveltejs/adapter-node: next => 1.0.0-next.55 
    @sveltejs/kit: next => 1.0.0-next.201 
    svelte: ^3.44.2 => 3.44.2

Severity

serious, but I can work around it

Additional Information

No response