How do you enable profiling?

[iand675]

Hi, I am trying to figure out how to enable profiling on a package I maintain (along with its dependencies). Can you provide any guidance about how to make that work with haskell-flake?

[srid]

In overrides, do:

mypackage = pkgs.haskell.lib.enableLiraryProfiling super.mypackage;

eg: https://github.com/srid/emanote/blob/cedd7d8cde17e0dbe96b2b9d2210d8da7d2e2d01/flake.nix#L74-L76

[iand675]

When I do that, I get a lot of errors about how the underlying libraries aren't installed with profiling support:

    Could not find module ‘Control.Exception’
    Perhaps you haven't installed the profiling libraries for package ‘base-4.17.0.0’?
    Use -v (or `:set -v` in ghci) to see a list of the files searched for.

Do I have to override all of the transitive dependencies the way you specified to make it work?

[srid]

I believe profiling is enabled by default in pkgs.haskellPackages. What is your basePackages? Your flake.nix?

[iand675]

Here is the flake in question. At the moment I'm trying to use the default repl on darwin aarch64 https://github.com/iand675/hs-opentelemetry/blob/improved-dux/flake.nix

[srid]

You are using pkgs.haskell.packages.${compilerVersion}. I know that library profiling is enabled by default in pkgs.haskellPackages. You could try asking in https://app.element.io/#/room/#haskell:nixos.org

But yes if library profiling is disabled by default in those package sets, you'd have to mapAttrs over them and enable it in the overrides, which would trigger compilation of the whole package set (in use).