Order of application of extensible-self?

[adrianparvino]

stackage2nix/src/Distribution/Nixpkgs/Haskell/Stack/PrettyPrinting.hs

Line 144 in 17526c8

, attr "extensible-self" "makeExtensible (extends overrides (extends configurationCommon (extends packageSetConfig (extends compilerConfig (extends configurationNix haskellPackages)))))"

Why does configurationCommon takes precedence over the more specific packageSetConfig and compilerConfig?

[4e6]

configurationCommon is a quick and dirty way to override a Haskell packages set generated by stackage2nix.

For example, stackage2nix generates following files for lts-10.0 packages set:
https://github.com/typeable/nixpkgs-stackage/tree/master/stackage/lts-10.0

stackage/lts-10.0
├── configuration-packages.nix
├── default.nix
└── packages.nix

You can drop-in a file named configuration-common.nix to override the generated packages set. Otherwise, you'd need to import the packages and pass the overrides function as README#override-result-derivation example shows.
It's probably a bad naming too, because it has nothing to do with the configurationCommon from nixpkgs.