Re: [Haskell-beginners] Stack minimal dependency specification, or dependency tree output

On Feb 24, 2016, at 5:10 PM, Lyndon Maydwell wrote:

Hi Mark,

That would be great, and I have tried that, but there is one issue that caused me to take the current approach instead.

The issue is that every change to

* Setup.hs * simple-app.cabal * stack.yaml

will cause the docker to consider the copy statement

...

COPY LICENSE Setup.hs simple-app.cabal stack.yaml /app/

as a fresh checkpoint, and make the cache unusable. Since I've frequently changing stack.yaml, and app.cabal, this won't help me much.

Not sure if there's a way around that with this method.

Let me know if I've overlooked something with your approach!

- Lyndon

...

I have found that it works well to use a dummy file that does not change in order to set up a cache. You can then copy over the real file; preserving the cached docker layer. Josh