stack path

[snoyberg]

I closed an issue about this previously, but after discussing with @chrisdone we should implement it. Will have information about:

• Which GHC is being used
• Where log files are stored
• Package databases

[DanBurton]

@snoyberg @chrisdone the implementation was not obvious to me, so I stubbed it out. I presume you two probably have the knowledge to trivially implement it from here, or give me some pointers on how to go about discovering these values?

Also, I believe the code as written will create a project file if it doesn't exist, and that's probably not what we want it to do. But I don't see any other way to get a BuildConfig, which I presume has the necessary components to determine these paths.

[snoyberg]

@DanBurton Reassigning to you actually. Please ping me on Slack to ask whatever questions you have about where to get this information.

[3noch]

Also would be nice to know the path to built binaries.

[3noch]

I'm just one person, but I'd really like to have this, at least for GHC. I tried to figure it out, but it's over my head. I'd be happy to take some pointers.

[3noch]

For now I can just do stack exec -- which ghc.

[chrisdone]

Done. Passing over to @snoyberg to review. Here's how it looks:

chris@retina:~/Work/stack$ stack path --help
Usage: stack path [--global-stack-root] [--project-root] [--config-location]
                  [--bin-path] [--ghc-paths] [--local-bin-path]
                  [--extra-include-dirs] [--extra-library-dirs]
                  [--snapshot-pkg-db] [--local-pkg-db] [--snapshot-install-root]
                  [--local-install-root] [--dist-dir]
  Print out handy path information

Available options:
  --global-stack-root      Global stack root directory
  --project-root           Project root (derived from stack.yaml file)
  --config-location        Configuration location (where the stack.yaml file is)
  --bin-path               PATH environment variable
  --ghc-paths              Installed GHCs (unpacked and archives)
  --local-bin-path         Local bin path where stack installs executables
  --extra-include-dirs     Extra include directories
  --extra-library-dirs     Extra library directories
  --snapshot-pkg-db        Snapshot package database
  --local-pkg-db           Local project package database
  --snapshot-install-root  Snapshot installation root
  --local-install-root     Local project installation root
  --dist-dir               Dist work directory
chris@retina:~/Work/stack$ stack path 
Caching build plan
Populated index cache.
global-stack-root: /home/chris/.stack/
project-root: /home/chris/Work/stack/
config-location: /home/chris/Work/stack/stack.yaml
bin-path: /home/chris/.stack/snapshots/x86_64-linux/lts-2.9/7.8.4/bin:/home/chris/.local/bin/:/opt/firefox/:/opt/ghc/7.8.4/bin:/home/chris/Projects/xmonad-chrisdone/dist/build/xmonad-chrisdone:/home/chris/.local/bin/:/opt/firefox/:/opt/ghc/7.8.4/bin:/home/chris/Projects/xmonad-chrisdone/dist/build/xmonad-chrisdone:/home/chris/.cabal/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
ghc-paths: /home/chris/.stack/programs/x86_64-linux/
local-bin-path: /home/chris/.local/bin/
extra-include-dirs: 
extra-library-dirs: 
snapshot-pkg-db: /home/chris/.stack/snapshots/x86_64-linux/lts-2.9/7.8.4/pkgdb/
local-pkg-db: /home/chris/Work/stack/.stack-work/install/x86_64-linux/lts-2.9/7.8.4/pkgdb/
snapshot-install-root: /home/chris/.stack/snapshots/x86_64-linux/lts-2.9/7.8.4/
local-install-root: /home/chris/Work/stack/.stack-work/install/x86_64-linux/lts-2.9/7.8.4/
dist-dir: .stack-work/dist/x86_64-linux/Cabal-1.18.1.5/
chris@retina:~/Work/stack$ stack path --snapshot-pkg-db 
snapshot-pkg-db: /home/chris/.stack/snapshots/x86_64-linux/lts-2.9/7.8.4/pkgdb/
chris@retina:~/Work/stack$ 

[snoyberg]

LGTM. Can you update the ChangeLog about this?

[chrisdone]

Done!

[3noch]

Can we add an option that shows the path to the version of GHC that will actually be used to build?

[chrisdone]

Yeah, that can be included.