Failed to load interface for 'Prelude' when invoking GHCi with test target

[mrkkrp]

I'm trying to switch to Stack completely and so I need to use it to run REPL. As I understand stack ghci is the correct command for this. I have a project with a library, two test suites and a benchmark. This command works OK:

$ stack ghci myproject:lib --no-load

Then I can use :m to load file of interest (otherwise all modules are loaded at once, given that some of them are intended to be imported qualified, it's not what I usually want). However, when I need to work with tests, I get this:

$ stack ghci myproject:test:mytestsuite --no-load
Using main module: Package `mypackage' component test:mytestsuite with main-is file: /some/path/here
Configuring GHCi with the following packages: myproject
GHCi, version 7.10.2: http://www.haskell.org/ghc/  :? for help

<interactive>:1:1:
    Failed to load interface for ‘Prelude’
    It is a member of the hidden package ‘base-4.8.1.0’.
    Use -v to see a list of the files searched for.

How is that? The test suite specifies base >= 4.6 && < 5 in Cabal file, so it cannot be hidden. I would normally think that this is sort of problem with my configuration, but stack test and other commands work fine.

[mrkkrp]

Living without REPL sometimes can be quite painful. Is there something I can do to use REPL with non-default build target?

[mgsloan]

@mrkkrp I figured that your repro case is stack ghci megaparsec:tests. That should indeed work. I fixed 3 things and now it does :D

Can you please close this issue if the latest stack version fixes the issue?

[mrkkrp]

@mgsloan, It works now! Thank you very much.

[mac10688]

I have the same issue. How did you upgrade your version of stack? I did "stack upgrade" but it said I'm at the latest. I have a workaround for now. I just ":l test/test.hs", but it would be nice to just load my test suite directly.

[mgsloan]

@mac10688 stack upgrade --git to get the latest development version.