ngtools/webpack Function expressions are not supported in decorators in 'NgModule'

Versions

npm 4.2.0
macOS Sierra
@angular/compiler-cli: ^5.2.1

Repro steps

To recreate, clone this repo and then do the following…

cd <repoDir>
git checkout functions
cd module
yarn install
cd ../app
yarn install
yarn run build:prod

Observed behavior

Upon compiling with the last statement I get …

ERROR in ../module/src/utils/module.ts(5,2): Error during template compile of 'Utils'
  Function expressions are not supported in decorators in 'NgModule'
    'NgModule' contains the error at @angular/core/core.ts(194,31)
      Consider changing the function expression into an exported function.

But doing yarn run build:dev which does not use AoT compilation works fine. You can point your browser to <repoDir>/app/public/index.html to see the results.

Desired behavior

To be able to use AoT compilation with this setup.

Mention any other details that might be useful (optional)

Notice that the tsconfig.json file has a path set to look for code in the modules directory. Not entirely sure if it’s due to that or not but I have multiple apps sharing code from a large base that I have not made into modules due to other issues.

[crowmagnumb]

Did you even look at my repo? Did you assume I did absolutely no homework on this? I don’t think the case I have is any of those outlined in any of the links above. Sorry, but I spent a great amount of time reducing my problem to a very simple repo for you to look at and I feel like I was completely dismissed out of hand.

[crowmagnumb]

Thank you @filipesilva! I think you and @devoto13 may be right that it has to do with my home-grown sub-module setup which up until the very latest version of Angular, namely 5.2 (been doing it this way since Angular 1.3!), has worked just fine. But now I’ve run into this this problem as well that looks to also be related to this. My actual module is huge and I had a ton of problems getting it to work with ng-packagr a number of months ago. While I might attempt that again, yarn workspaces also looks like a great possible solution. I’ll give those a go. Thank you!