Compilation result may depend on the stack command order in case of mixins usage

[rvem]

General summary/comments (optional)

If the project uses mixins to hide Prelude from the base package and custom prelude,
compilation result may depend on the stack command order.

Steps to reproduce

Build the following sample stack project.

stack.yaml:

resolver: lts-16.5

packages:
- .

extra-deps:
  - morley-prelude-0.3.0@sha256:9e9473ac14cfa206adf0a3700764c0251de05042f1fe45daf9cb8556079ae663,2085

package.yaml:

name:                stack-investigation
version:             0.1.0.0
github:              "githubuser/stack-investigation"
license:             BSD3
author:              "Author name here"
maintainer:          "[email protected]"
copyright:           "2020 Author name here"

extra-source-files:
- README.md
- ChangeLog.md

# Metadata used when publishing your package
# synopsis:            Short description of your package
# category:            Web

# To avoid duplicated efforts in documentation and dealing with the
# complications of embedding Haddock markup inside cabal files, it is
# common to point users to the README.md file.
description:         Please see the README on GitHub at <https://github.com/githubuser/stack-investigation#readme>

dependencies:
  - name: base
    version: ">= 4.7 && < 5"
    mixin: [hiding (Prelude)]

library:
  source-dirs: src
  dependencies:
  - morley-prelude

executables:
  stack-investigation-exe:
    main:                Main.hs
    source-dirs:         app
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - stack-investigation
    - morley-prelude

tests:
  stack-investigation-test:
    main:                Spec.hs
    source-dirs:         test
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - stack-investigation
    - morley-prelude
    - network

1. Use clear ~/.stack, .stack-work and run stack test for the current project. The build succeeds.

2. Use clear ~/.stack, .stack-work and run stack build && stack test. The build fails with the following error:

network          > [1 of 2] Compiling Main             ( /tmp/stack-38b10cd0c119f260/network-3.1.1.1/Setup.hs, /tmp/stack-38b10cd0c119f260/network-3.1.1.1/.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.0.1.0/setup/Main.o )
network          > 
network          > /tmp/stack-38b10cd0c119f260/network-3.1.1.1/Setup.hs:1:8: error:
network          >     Ambiguous module name `Prelude':
network          >       it was found in multiple packages:
network          >       base-4.13.0.0 morley-prelude-0.3.0
network          >   |
network          > 1 | module Main (main) where
network          >   |        ^^^^

Looks like the problem is caused by the fact that network is compiled after morley-prelude
in the latter case, and before it in the former one.

Expected

Both command sequences end in a successful build

Actual

stack build && stack test failed with ambiguous Prelude error.
What actually happened.

Stack version

2.5.0.1

Method of installation

Linux binary from Github release.

Archive with sample project sources

stack-project.zip