Provide an option to configure the location `.stack-work` directory

[Gabriella439]

Right now I'm working on implementing a Haskell plugin for Twitter's build tool, pants, and one thing we'd like to have is the ability to configure the location of the ~/.stack and .stack-work directories under directories managed by the pants tool.

If this is already possible, just let me know, but the last time I checked I couldn't figure out how to do this.

[borsboom]

You can set the STACK_ROOT environment variable to override the location of ~/.stack. .stack-work is not currently overridable.

[borsboom]

I don't think overriding .stack-work would be too hard to implement, and a PR would be welcome.

[Gabriella439]

Thanks for the STACK_ROOT tip! That helps a lot

[UnkindPartition]

I would also like to see this implemented.

My use case is that I need to produce two build flavors: with and without hpc. The best way (for incremental compilation) to do this is to build them in two different build trees. I plan to work around this for now by making .stack-work an alternating symlink.

[mrkkrp]

In case nobody is doing this already, I try could to implement the feature (once my current PR is merged). We could make STACK_LOCAL environment variable override .stack-work. If you have alternative ideas in mind, tell me.

[Gabriella439]

Shouldn't this be passed on the command line? Programming using environment variables is very error-prone: if you make a typo in the environment variable name nothing will catch the error

[mgsloan]

@Gabriel439 Good point, this makes more sense as a commandline argument, since it's probably something local to your current build. STACK_ROOT is shared globally, which is why it makes sense to have it as an environment variable.

@mrkkrp Feel free to add this!

[mrkkrp]

@Gabriel439, @feuerbach, this is solved now. You can add work-dir parameter with relative directory to use instead of .stack-work in stack.yaml or override it on command line via --work-dir=some-directory thing.

Here is the PR: #1442.

@mgsloan, Looks like this may be closed.

[mgsloan]

@mrkkrp Thanks for implementing this!