stack build not working

[andrewthad]

Unfortunately, there aren't many details I can provide about this, but I figured I'd throw it up here just so that if anyone else had the same issue, it could get noticed. Basically, stack quit building my project. I had been using lts-2.14 and stack-0.0 and everything was working. Today, I made some changes and ran stack build and nothing happened. I deleted the .stack-work directory. Still nothing. Upgraded to stack-0.1. Nothing. I'm switching to lts-2.15 right now to see if that can somehow get stack out of whatever it's trapped in.

[mitchellwrosen]

stack build --verbose

[andrewthad]

Well, whatever had happened, that fixed it. I'll leave this open for a few days in case it has affected anyone else. If I don't hear anything, I'll assume it was some foolishness of my own.

[andrewthad]

@mitchellwrosen Dang. I just saw that.

[krisajenkins]

This is possibly a duplicate of #365. Sounds like the same symptom.

[quyse]

I just saw the same symptoms as well: stack build does nothing, and removing .stack-work and/or various stack's global caches changes nothing. Until I realized that I have STACK_YAML environment variable set to a different stack.yaml in different project, and the current directory is outside of that project, so I guess stack just decides there's nothing to build here.
Actually stack build --verbose prints enough information to understand this mistake, but it may be improved though, i.e. print something clear like 'nothing to build because of ...', at least in verbose mode.

[snoyberg]

I'm open to ideas here, but in all cases, it would be "Nothing to build because all packages are built and have no modified files and no flags have changed" :). I suppose we could list all of the packages we checked, or give an error message when the packages list was empty. I'm open to ideas here to avoid user complication, I just don't have any good ideas :)

[radix]

This makes me wonder if STACK_YAML is a bad idea, and people should just use --stack-yaml. At the very least, people should avoid exporting it in their interactive shell sessions. Perhaps a FAQ entry?

[snoyberg]

The original use case it was designed for is when you're working on a project, and want to compile some code via stack ghc or the like in a separate directory. Having to use --stack-yaml in that case would be inconvenient.

For the record, there's (supposed to be) a message on the console each time STACK_YAML is used.

[snoyberg]

I don't see anything clearly actionable without breaking some people's workflows, so closing. If someone has a suggestion to move forward, please bring it up.