When intero-mode tries automatically installing Intero, it produces the following error:
Intero is not installed in the Stack environment.
Installing intero-0.1.23 automatically ...
Error: While constructing the build plan, the following exceptions were encountered:
In the dependencies for intero-0.1.23:
ghc-8.2.2 from stack configuration does not match >=7.8 && <8.2.2 (latest matching version
is 8.2.1)
needed since intero is a build target.
Some potential ways to resolve this:
* Recommended action: try adding the following to your extra-deps
in <project directory>\stack.yaml:
- ghc-8.2.1
* Set 'allow-newer: true' to ignore all version constraints and build anyway.
* You may also want to try using the 'stack solver' command.
Plan construction failed.
Could not install Intero!
We don't know why it failed. Please read the above output and try
installing manually. If that doesn't work, report this as a
problem.
WHAT TO DO NEXT
If you don't want to Intero to try installing itself again for
this project, just keep this buffer around in your Emacs.
If you'd like to try again next time you try use an Intero
feature, kill this buffer.
This started happening after I upgraded to lts-10.0, but even before that I was having problems with Intero (I reported it at https://github.com/commercialhaskell/intero/issues/499). What is happening here and how can I fix it? I'm using emacs and spacemacs on Windows 10.
I'm not at all an emacs expert, but I do know that the intero-mode elisp files specify an exact version of the intero Haskell package. You'll need to update to the newer emacs package. I don't know how you installed intero-mode in the first place, but I'm going to guess that (like me) you got it off MELPA. Ultimately I moved over to installing via Git so I could more easily upgrade and test features that hadn't been released on MELPA yet. You can do this by:
~/.emacs.d/vendor/intero~/.emacs: (load-file "~/.emacs.d/vendor/intero/elisp/intero.el")