## Summary When loading certain projects into ghci, the first call to `main` after a `:l` or a `:r` will take a few seconds until the `main` is actually executed. This makes live reloading in IHP very slow. E.g. when a user changes some haskell code in an IHP project, the IHP dev server will stop the current app in ghci and trigger a `:r`. The IHP dev server watches for a message such as `Ok, 199 modules loaded.` and then triggers a `:main`. This call to `:main` now takes a couple of seconds to execute, even though ghci already told is that it has reloaded all necessary files. Here's a video showing the problem:  The `Main entered` message appears as expected, but there's a long delay between when I enter `main` and when the message appears. The `putStrLn "Main entered"` is the first operation in that module: ```haskell main :: IO () main = do putStrLn "Main entered" IHP.Server.run config ``` ## Steps to reproduce This problem also happens with the IHP repo itself, so we can use that to reproduce it. To load IHP into ghci, [you need to install nix and devenv.sh first](https://devenv.sh/getting-started/). Once `devenv.sh` is installed, run `cachix use digitallyinduced` to enable our binary cache for a faster build time. Now you can reproduce it by running these commands: ```bash # Clone the repo git clone https://github.com/digitallyinduced/ihp.git cd ihp # This will enter a shell with all dependencies nix develop --impure # Run ghci ghci :l Test/Main.hs # => Ok, 152 modules loaded. main # ... now it takes a few seconds until the app starts up ``` ## Expected behavior Calling `main` should directly start the app, without a delay of a few seconds. ## Environment * GHC version used: 9.4.4 + 9.6.2 * Operating System: macOS (This problem might be mac specific, I've not seen similiar behaviour on linux computers) * System Architecture: x86_64 * Project Size: This problem seems to only appear in projects with more than a few modules. On a fresh IHP project with 20 modules, the `:main` is typically instant.