How to set reExecL as True?

[leptonyu]

I run stack ghci into ghci environment, and want run test using :!stack test, but it failed.

Control.Exception.Safe.throwString called with:

In Nix shell but reExecL is False
Called from:
  throwString (src/Stack/Runners.hs:120:18 in stack-2.1.3-F7MWgE4o5YoAS7Zt7rEwj6:Stack.Runners)

How to fix this?

[mattaudesse]

Hey @leptonyu - sorry for the delayed response.

Were you able to figure this out? I'm having trouble reproducing the error, so it'd help if you could share a link to a git repo that fails with the message in your output (or steps to build one).

Which versions of stack and nix do you have installed?

[leptonyu]

@mattaudesse

plz use repo to test.

My stack version is 2.13 and nix version is 2.2.2

stack ghci
Configuring GHCi with the following packages: boots, boots-app
GHCi, version 8.6.5: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /Users/daniel/Documents/code/shell/ghci
[1 of 8] Compiling Boots.App.Internal ( /Users/daniel/Documents/code/boots/boots-app/src/Boots/App/Internal.hs, interpreted )
[2 of 8] Compiling Boots.Factory    ( /Users/daniel/Documents/code/boots/boots/src/Boots/Factory.hs, interpreted )
[3 of 8] Compiling Boots.App        ( /Users/daniel/Documents/code/boots/boots-app/src/Boots/App.hs, interpreted )
[4 of 8] Compiling Boots.Factory.Salak ( /Users/daniel/Documents/code/boots/boots-app/src/Boots/Factory/Salak.hs, interpreted )
[5 of 8] Compiling Boots.Factory.Vault ( /Users/daniel/Documents/code/boots/boots-app/src/Boots/Factory/Vault.hs, interpreted )
[6 of 8] Compiling Boots.Factory.Logger ( /Users/daniel/Documents/code/boots/boots-app/src/Boots/Factory/Logger.hs, interpreted )
[7 of 8] Compiling Boots.Factory.Application ( /Users/daniel/Documents/code/boots/boots-app/src/Boots/Factory/Application.hs, interpreted )
[8 of 8] Compiling Boots            ( /Users/daniel/Documents/code/boots/boots-app/src/Boots.hs, interpreted )
Ok, 8 modules loaded.
Loaded GHCi configuration from /private/var/folders/lh/6nc659bd3hx059sw2cn4zhjr0000gn/T/haskell-stack-ghci/0e0d4d57/ghci-script
λ> :!stack test
Control.Exception.Safe.throwString called with:

In Nix shell but reExecL is False
Called from:
  throwString (src/Stack/Runners.hs:120:18 in stack-2.1.3-F7MWgE4o5YoAS7Zt7rEwj6:Stack.Runners)

and I put some config in the ~/.stack/config.yaml

nix:
  enable: true
  add-gc-roots: true
  packages:
    - zlib
    - libffi
    - darwin.apple_sdk.frameworks.CoreServices
    - darwin.apple_sdk.frameworks.Foundation
    - darwin.apple_sdk.frameworks.Cocoa

[mattaudesse]

Thanks @leptonyu - with those steps I can definitely reproduce the problem now.

I experimented a bit to see if I could fix it easily but based on this commit I think @snoyberg might be the best person to comment.

I'm guessing you've already tried this, but does stack test work for you when run outside of stack ghci? It does for me.

[leptonyu]

@mattaudesse Yes, I can work with 2 windows open.

I have two scenarios, but the second has no workaround.

First is some customized commands, like

def ho   \x -> return $ ":!stack exec hoogle -- " ++ x

This can be replaced by hoogle.

Second is ghcid, it has an option --test which can set command to run after successful loading.
So I need run stack in stack.

ghcid --test ':!stack test' --reload .

[snoyberg]

Both the Docker and Nix codepaths (which both leverage the same reExecL feature) are notoriously susceptible to breaking in weird ways when their environment is modified in unexpected ways. We've tried to lock things down to ensure that they are run in normal environments. The exact thing you're trying to accomplish may run just fine, but it's untested, and I'd rather encourage people towards using tested codepaths than try to figure out exceptions we can start adding.

If you really want to, deleting the relevant env vars from within ghci would probably help in your use case.

[leptonyu]

Thanks, it works by removing STACK_IN_NIX_SHELL.

ghcid --test ':!unset STACK_IN_NIX_SHELL && stack test' --reload .

[freeman42x]

@leptonyu how could I remove STACK_IN_NIX_SHELL when doing a stack build ?