after upgrading to nixos-19.03 stack started misbehaving:
$ stack ghci
error: attribute 'ghc863' missing, at (string):1:43
(use '--show-trace' to show detailed location information)
While a simple
stack --help works (i.e. the expected output is produced).
Am I doing something wrong or should I report a bug?
Could you provide a bit more information?
Like, could you provide the
--show-trace output, the
default.nix and the
stack.yaml that you are uisng?
haskell.compiler.ghc863 was removed from
nixpkgs. You may want to use a
stack resolver that points to
You can alternatively point stack to a version of nixpkgs that has ghc863
~/.stack and running stack againg solved the problem
How? Shouldn’t it have still been looking for ghc863, which still shouldn’t have existed? What GHC version is getting?
I confirm both the problem (upgrading to 19.03 breaks stack) and the effectiveness of the solution from @wfranzini (delete .stack directory and invoking stack again).
Please note that i get this error minutes ago, after executing <nixos-rebuild switch --upgrade> from the stable channel, so it is still an issue.
little after that, trying to work on another project, i got the message “attribute ‘ghc843’ missing”…
So, this don’t solve for everithing, just for the originally reported issue. And, the same error is informed if you try to use --trace
It doesn’t for
stack repl at least.