Stack reclones git packages too eagerly causing unnecessary compilation

[parsonsmatt]

General summary/comments (optional)

The Problem:

I have a stack.yaml with some packages:

packages:
  - foobar/
  - foobar-models/
  - location:
     git: git@github.com:qrilka/esqueleto
     commit: 607f6692f0539df4e4f0e1d14beffcc6df2cdc49
    extra-dep: true

foobar-models takes a really long time to compile, so it's split off into it's own package. Generally this is great! However, the esqueleto dependency gets confused, and reclones pretty regularly, causing a complete rebuild of foobar-models and foobar.

Steps to reproduce

I don't have any public projects that I can reproduce this with, but I can attempt to get a minimal reproduction of a proprietary project if it would help.

Expected

Git dependencies are only cloned/compiled once per change of the stack.yaml entry for them.

Actual

Git dependencies are rebuilt regularly, causing multiple packages to be rebuilt.

Stack version

$ stack --version
Version 1.2.1, Git revision b75ec0cf82c2e8d1cb6f1bf85cf0244ada55cc61 x86_64 hpack-0.14.1

Method of installation

stack upgrade --git

[chreekat]

This might be a dupe of, or related to, #1295

[mgsloan]

Is this still happening with stack 1.4? It would indeed be good to have a minimal repro. Closing for now, feel free to reopen with repro if it still reproduces