From a375d4bfc35998aec36ee15b7c71d99a5b78fa2d Mon Sep 17 00:00:00 2001
From: Graham Christensen <graham@grahamc.com>
Date: Tue, 18 Dec 2018 10:50:53 -0500
Subject: [PATCH] stdenv: shorten evaluation errors when in Hydra
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Hydra's page showing evaluation errors is about a mile long, showing
buckets of user-friendly errors, like this:

    in job ‘seyren.aarch64-linux’:
    Package ‘oraclejre-8u191’ in /nix/store/fa9zzkbljkvdavwzirkrr5irg25ymbjl-source/pkgs/development/compilers/oraclejdk/jdk-linux-base.nix:71 has an unfree license (‘unfree’), refusing to evaluate.

    a) For `nixos-rebuild` you can set
      { nixpkgs.config.allowUnfree = true; }
    in configuration.nix to override this.

    b) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
      { allowUnfree = true; }
    to ~/.config/nixpkgs/config.nix.

    in job ‘jetbrains.webstorm.x86_64-linux’:
    Package ‘webstorm-2018.3.1’ in /nix/store/fa9zzkbljkvdavwzirkrr5irg25ymbjl-source/pkgs/applications/editors/jetbrains/default.nix:230 has an unfree license (‘unfree’), refusing to evaluate.

    a) For `nixos-rebuild` you can set
      { nixpkgs.config.allowUnfree = true; }
    in configuration.nix to override this.

    b) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
      { allowUnfree = true; }
    to ~/.config/nixpkgs/config.nix.

This makes it extremely hard to find actual issues in the output. This
patch set makes the output much more condensed in Hydra:

    Failed to evaluate nifticlib-2.0.0: «unsupported»: is not supported on ‘x86_64-apple-darwin’
    Failed to evaluate dmd-2.081.2: «unsupported»: is not supported on ‘aarch64-unknown-linux-gnu’
    Failed to evaluate dmdBuild-2.081.2: «unsupported»: is not supported on ‘aarch64-unknown-linux-gnu’
    Failed to evaluate ldc-1.11.0: «unsupported»: is not supported on ‘aarch64-unknown-linux-gnu’
    Failed to evaluate ldcBuild-1.11.0: «unsupported»: is not supported on ‘aarch64-unknown-linux-gnu’
    Failed to evaluate ldc-0.17.5: «unsupported»: is not supported on ‘aarch64-unknown-linux-gnu’
    Failed to evaluate ldcBuild-0.17.5: «unsupported»: is not supported on ‘aarch64-unknown-linux-gnu’
---
 pkgs/stdenv/generic/check-meta.nix | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/pkgs/stdenv/generic/check-meta.nix b/pkgs/stdenv/generic/check-meta.nix
index d09dff10b27..fe0c8cfad91 100644
--- a/pkgs/stdenv/generic/check-meta.nix
+++ b/pkgs/stdenv/generic/check-meta.nix
@@ -4,6 +4,10 @@
 { lib, config, hostPlatform, meta }:
 
 let
+  # If we're in hydra, we can dispense with the more verbose error
+  # messages and make problems easier to spot.
+  inHydra = config.inHydra or false;
+
   # See discussion at https://github.com/NixOS/nixpkgs/pull/25304#issuecomment-298385426
   # for why this defaults to false, but I (@copumpkin) want to default it to true soon.
   shouldCheckMeta = config.checkMeta or false;
@@ -141,10 +145,12 @@ let
 
   handleEvalIssue = attrs: { reason , errormsg ? "" }:
     let
-      msg = ''
-        Package ‘${attrs.name or "«name-missing»"}’ in ${pos_str} ${errormsg}, refusing to evaluate.
+      msg = if inHydra
+        then "Failed to evaluate ${attrs.name or "«name-missing»"}: «${reason}»: ${errormsg}"
+        else ''
+          Package ‘${attrs.name or "«name-missing»"}’ in ${pos_str} ${errormsg}, refusing to evaluate.
 
-      '' + (builtins.getAttr reason remediation) attrs;
+        '' + (builtins.getAttr reason remediation) attrs;
 
       handler = if config ? "handleEvalIssue"
         then config.handleEvalIssue reason