When overriding installPhase, you should also provide runHook preInstall and runHook postInstall. Though, in this case, why not rely on the default installPhase and specify installTargets = [ "install" "install-docs" ];?

When overriding installPhase, you should also provide runHook preInstall and runHook postInstall.

Why? As I understand it, the hooks are stdenv hooks, not derivation hooks, and are for the derivation to use if it wants to. It’s not like the hooks are a generic, consistent way to allow users of packages to insert extra commands, because if I had used preInstall here, somebody overriding that would break the package.

Though, in this case, why not rely on the default installPhase and specify installTargets = [ "install" "install-docs" ];?

Because I didn’t know about those! Thanks!

You would use pkg.overrideAttrs (attrs: {postInstall = (attrs.postInstall or "") + ''foo'';}). I keep recommending adding hooks because I have seen their lack of confuse nixpkgs users several times. Granted, nine times out of ten it was about fixupPhase hooks, but installPhase was there too. I think consistency is useful for reducing the amount of head scratchers.

Fair enough — thanks for explaining!

Same here. buildFlags = [ "libs" "tools" ]; should work, please add an explanation comment otherwise.

Weird that there’s no buildTargets, defaulting to []…