Scully: Error during file write Error: ENOENT: no such file or directory, mkdir

Question

I'm using Scully to generate static pages for my dynamic routes. See my configuration below:

export const config: ScullyConfig = {
  projectRoot: './src',
  projectName: 'myNgProject',
  outDir: './dist/static',
  routes: {
    '/product/:permalink': {
      type: 'json',
      permalink: {
        url: 'https://api.my-ng-project.com/products',
        property: 'permalink',
        resultsHandler: (data:any) => {
          let products = data.map(data, (x:any) => {
            return { 'permalink' : x.permalink }
          })
          return products
        },
      },
    },
  },

Here's an excerpt of my route config:

const routes: Routes = [
  {
    path: '', component: MainLayoutComponent, children: [
      { path: '', component: IndexComponent },
      { path: 'login', component: LoginComponent },
      { path: 'profile', component: ProfileComponent },
      { path: 'orders', component: OrdersComponent },
      { path: 'product/:permalink', component: ProductComponent },
    ]
  }
]

Scully is working on non-dynamic routes but fails on /product/:permalink routes. See error below:

Not sure what I am missing here but it looks like Scully is trying to literally create a folder named product/:permalink instead of product/product1, etc.

Anybody knows how to solve this?