Not prompted to do stack docker pull

[ivan-m]

General summary/comments (optional)

The documentation states that:

The first time you run a command with a new image, you will be prompted to run stack docker pull to pull the image first.

However, instead I received an error message.

Steps to reproduce

I don't know if this is relevant, but due to corporate policies I have to access Docker Hub via a mirror; I shall refer to this as corp.mirror/remote.

I have this in my stack.yaml:

resolver: lts-8.5

docker:
  enable: false
  repo: corp.mirror/remote/fpco/stack-build
  run-args:
    - "--net=bridge"

$ stack build --docker
Running /usr/local/bin/docker inspect corp.mirror/remote/fpco/stack-build:lts-8.5 exited with ExitFailure 1

[]

Error: No such object: corp.mirror/remote/fpco/stack-build:lts-8.5

Expected

stack build --docker should tell me I need to do a stack docker pull.

Actual

$ stack build --docker --verbose

# Snipping stack versioning output

2017-08-09 13:23:26.609217: [debug] Checking for project config at: /project/path/stack.yaml
@(Stack/Config.hs:974:9)
2017-08-09 13:23:26.609866: [debug] Loading project config file stack.yaml
@(Stack/Config.hs:999:13)
2017-08-09 13:23:26.612122: [debug] Run process: /usr/local/bin/docker --version
@(System/Process/Read.hs:306:3)
2017-08-09 13:23:26.627167: [debug] Process finished in 14ms: /usr/local/bin/docker --version
@(System/Process/Read.hs:306:3)
2017-08-09 13:23:26.627709: [debug] Run process: /usr/local/bin/docker inspect corp.mirror/remote/fpco/stack-build:lts-8.5
@(System/Process/Read.hs:306:3)
Running /usr/local/bin/docker inspect corp.mirror/remote/fpco/stack-build:lts-8.5 exited with ExitFailure 1

[]

Error: No such object: corp.mirror/remote/fpco/stack-build:lts-8.5

(stack docker pull does indeed work.)

Stack version

$ stack --version
Version 1.5.0 x86_64

Method of installation

• Using nix on macOS.

[ivan-m]

I'm using Docker for Mac 17.0.6.0 with this.

I think the issue is here: if I run docker inspect manually:

$ /usr/local/bin/docker inspect corp.mirror/remote/fpco/stack-build:lts-8.5
[]
Error: No such object: corp.mirror/remote/fpco/stack-build:lts-8.5

There is now an extra []\n more than expected by missingImagePrefixes. This may be due to a change in behaviour from Docker.

[borsboom]

It should be a pretty easy fix... unfortunately parsing CLI output is going to tend toward this kind of breakage (but the Docker API is even more prone to breakage, so I don't know if using that directly would be an improvement).

Aside: since --install-ghc is now default behaviour, an analogous change would be to make --docker-auto-pull enabled by default. I've opened #3332 to track that change.

[snoyberg]

This was addressed by #4604