Flags in cabal files

Question

I am following the user-guide for package developing: https://www.haskell.org/cabal/users-guide/developing-packages.html#quickstart

I got stuck in the Flags

Answer 1

With Stack, use

stack build --flag :debug

to set debug flag to True for , or use --flag '*:debug' to set debug flag to True for all packages. Replace debug with -debug to set debug flag to False.

You can also specify flag settings in a stack.yaml file. For example, to set debug flag to False for , add this to your stack.yaml:

flags:
  :
    debug: false