From ecd3990cd4bd76e15658975f2e6f523f805ce52e Mon Sep 17 00:00:00 2001
From: Jan Malakhovski <oxij@oxij.org>
Date: Tue, 2 Jan 2018 14:52:27 +0000
Subject: [PATCH] stdenv: provide `meta.evaluates`

This gives a way to see the result of `check-meta` without triggering any assertions.
---
 pkgs/stdenv/generic/check-meta.nix      | 1 +
 pkgs/stdenv/generic/make-derivation.nix | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/pkgs/stdenv/generic/check-meta.nix b/pkgs/stdenv/generic/check-meta.nix
index 0a8dc006dc5..ed4a0e2d841 100644
--- a/pkgs/stdenv/generic/check-meta.nix
+++ b/pkgs/stdenv/generic/check-meta.nix
@@ -159,6 +159,7 @@ let
     executables = listOf str;
     outputsToInstall = listOf str;
     position = str;
+    evaluates = bool;
     repositories = attrsOf str;
     isBuildPythonPackage = platforms;
     schedulingPriority = str;
diff --git a/pkgs/stdenv/generic/make-derivation.nix b/pkgs/stdenv/generic/make-derivation.nix
index 41b0cc1a437..78e558daff1 100644
--- a/pkgs/stdenv/generic/make-derivation.nix
+++ b/pkgs/stdenv/generic/make-derivation.nix
@@ -211,6 +211,9 @@ rec {
         # Fill `meta.position` to identify the source location of the package.
         // lib.optionalAttrs (pos != null) {
           position = pos.file + ":" + toString pos.line;
+        # Expose the result of the checks for everyone to see.
+        } // {
+          evaluates = validity.valid;
         };
 
     in