Add --build-ghc-options flag for stack ghci (#971)

[chrisdone]

@bergmark

Now with --build-ghc-options you can retain the build flags:

bash-3.2$ stack build --test --ghc-options="-Wall -Werror"
stack-0.1.4.1: unregistering (components added: test:stack-test)
stack-0.1.4.1: configure
Configuring stack-0.1.4.1...
stack-0.1.4.1: build
[...]
Completed all 2 actions.
bash-3.2$ stack ghci --build-ghc-options="-Wall -Werror"
* * * * * * * *
The main module to load is ambiguous. Candidates are: 
Package `stack' component exe:stack with main-is file: /Users/chris/Work/stack/src/main/Main.hs
Package `stack' component test:stack-integration-test with main-is file: /Users/chris/Work/stack/test/integration/IntegrationSpec.hs
Package `stack' component test:stack-test with main-is file: /Users/chris/Work/stack/src/test/Test.hs
None will be loaded. You can specify which one to pick by: 
 1) Specifying targets to stack ghci e.g. stack ghci stack:exe:stack
 2) Specifying what the main is e.g. stack ghci --main-is stack:exe:stack
* * * * * * * *
Configuring GHCi with the following packages: stack
GHCi, version 7.10.2: http://www.haskell.org/ghc/  :? for help
unknown option: 'c'
[...]
*Control.Concurrent.Execute> :q
Leaving GHCi.
bash-3.2$ 

Also added a --pedantic arg:

bash-3.2$ stack build --test --pedantic
stack-0.1.4.1: unregistering (components added: test:stack-test)
stack-0.1.4.1: configure
Configuring stack-0.1.4.1...
stack-0.1.4.1: build
Preprocessing library stack-0.1.4.1...
[..]
Completed all 2 actions.
bash-3.2$ stack ghci --pedantic
* * * * * * * *
The main module to load is ambiguous. Candidates are: 
Package `stack' component exe:stack with main-is file: /Users/chris/Work/stack/src/main/Main.hs
Package `stack' component test:stack-integration-test with main-is file: /Users/chris/Work/stack/test/integration/IntegrationSpec.hs
Package `stack' component test:stack-test with main-is file: /Users/chris/Work/stack/src/test/Test.hs
None will be loaded. You can specify which one to pick by: 
 1) Specifying targets to stack ghci e.g. stack ghci stack:exe:stack
 2) Specifying what the main is e.g. stack ghci --main-is stack:exe:stack
* * * * * * * *
Configuring GHCi with the following packages: stack
GHCi, version 7.10.2: http://www.haskell.org/ghc/  :? for help
unknown option: 'c'
[...]
*Control.Concurrent.Execute> :q
Leaving GHCi.
bash-3.2$ 

If this sounds good I'll merge the redundant parts.

[bergmark]

I tried this branch but I don't see the --build-ghc-options flag:

$ stack --version
Version 0.1.4.1, Git revision ac59fd035fa87f5dc1dab4e27bc740fb5486b40b (1826 commits) X86_64
$ stack ghci --build-ghc-options='-Wall -Werror' silk-event
Usage: stack ghci [TARGET] [--ghc-options OPTION] [--pedantic]
                  [--ghc-options OPTION] [--with-ghc GHC] [--no-load]
                  [--package ARG] [--main-is TARGET]
  Run ghci in the context of project(s) (experimental)

[chrisdone]

Ah, looks like I regressed the argument name in ac59fd0. Pushed a fix.

[snoyberg]

@chrisdone Is this blocked on feedback from @bergmark?

[bergmark]

I tested it again now, thanks for the reminder.

I can't get this to work in a useful way for me, probably because of #743

* stack build --pedantic
<< Ooops my crappy package has warnings >>>
* stack ghci --build-ghc-options='-Wall -Werror' --pedantic my-crappy-package
generic-aeson-0.2.0.7: unregistering (flags changed from ["--ghc-options","-Wall","--ghc-options","-Werror"] to [])

(There also isn't a --dry-run for stack ghci by the way, it immediately unregister packages.)

So afaict there are these ways to handle the problem currently:

• If the project is small: Use stack build and stack ghci to work on overything at once
• Build one package at a time with stack ghci --pedantic foo (with flags) and install one by one using stack build foo (without flags). I'm not sure if there's a good way to know which package to install next while doing this
• Use stack build w/o package names or flags, and use ghci freely

I suppose what I want is a project-global configuration on what flags to use for packages.

[borsboom]

@chrisdone: is this PR still active?

[mgsloan]

Also worth considering how this relates to #1186

[mgsloan]

This is now available as --ghc-options, which get passed to both the build and ghci. GHCI specific options are passed via --ghci-options.