Revert "NixOS Integration Tests: Enable again for darwin"

[cole-h]

Reverts #303150

This broke ofborg's eval

cc @tfc

$ nix-env -qaP --no-name --out-path --arg checkMeta false --argstr path $PWD -f outpaths.nix --show-trace
error:
       … while evaluating call site

       at «none»:0: (source not available)

       … while calling anonymous lambda

       at /root/nixpkgs/outpaths.nix:48:12:

           47|   tweak = lib.mapAttrs
           48|     (name: val:
             |            ^
           49|       if name == "recurseForDerivations" then true

       … while evaluating call site

       at /root/nixpkgs/lib/attrsets.nix:1214:43:

         1213|     f:
         1214|     listToAttrs (map (n: nameValuePair n (f n)) names);
             |                                           ^
         1215|

       … while calling anonymous lambda

       at /root/nixpkgs/pkgs/top-level/release-lib.nix:145:6:

          144|   testOnCross = crossSystem: metaPatterns: f: forMatchingSystems metaPatterns
          145|     (system: hydraJob' (f (pkgsForCross crossSystem system)));
             |      ^
          146|

       … while evaluating call site

       at /root/nixpkgs/pkgs/top-level/release-lib.nix:145:14:

          144|   testOnCross = crossSystem: metaPatterns: f: forMatchingSystems metaPatterns
          145|     (system: hydraJob' (f (pkgsForCross crossSystem system)));
             |              ^
          146|

       … while calling 'hydraJob'

       at /root/nixpkgs/lib/customisation.nix:388:14:

          387|   */
          388|   hydraJob = drv:
             |              ^
          389|     let

       … while evaluating the attribute 'outPath'

       at /root/nixpkgs/lib/customisation.nix:404:13:

          403|           value = commonAttrs // {
          404|             outPath = output.outPath;
             |             ^
          405|             drvPath = output.drvPath;

       error: attribute 'out' missing

       at /root/nixpkgs/lib/customisation.nix:401:22:

          400|       makeOutput = outputName:
          401|         let output = drv.${outputName}; in
             |                      ^
          402|         { name = outputName;

[tfc]

I don't understand what the problem really is here. Do you have a link to a log file with more context?

Reverting this is bad because it breaks NixOS intefgration tests for macOS users which work just fine.

[cole-h]

The problem is that your PR causes ofborg to be unable to evaluate Nixpkgs anymore :P

Unfortunately, there is nothing more than what I just edited into the body above. Here's a gist from an actual PR against Nixpkgs that ran into this: https://gist.github.com/GrahamcOfBorg/a5b0c39f39058d8995cf54f554f5aabf

I'm not opposed to your PR at all! I'd just like it to not break ofborg's ability to evaluate PRs against Nixpkgs 😄

(If you have more than 32GiB of RAM, you can reproduce the issue with the same command I put in the PR body, where outpaths.nix is https://github.com/NixOS/ofborg/blob/released/ofborg/src/outpaths.nix. If you don't start swapping hard, it should take about 10 minutes to complete.)

[lilyinstarlight]

I don't understand what the problem really is here. Do you have a link to a log file with more context?

Reverting this is bad because it breaks NixOS intefgration tests for macOS users which work just fine.

The revert was needed because CI would have failed on initial PR and has broken eval on all PRs since it was merged (the original PR was merged before ofborg finished CI checks...)

You need to additionally remove this conditional in your original PR and replace it with inherit references;:

nixpkgs/pkgs/build-support/trivial-builders/test/default.nix

Lines 23 to 27 in 4e2ce36

	# VM test not supported beyond linux yet
	references =
	if stdenv.hostPlatform.isLinux
	then references
	else {};

Do please open a new PR that re-adds the systems and fixes that conditional!

[tfc]

Thank you everyone for trying to clarify. I do/did understand that the patch was blocking evaluation and would need to be reverted quickly to unblock others.

I do however not understand how the concatenation of the lists linux ++ darwin breaks evaluation. Thank you @lilyinstarlight for suggesting to use references, but i don't understand how to use this (the comment above also do not help me understand what this is supposed to do and where to place it). Can you please give me an example? Also, what do you mean with "remove this conditional" - i never added a conditional?

[lilyinstarlight]

I do however not understand how the concatenation of the lists linux ++ darwin breaks evaluation. Thank you @lilyinstarlight for suggesting to use references, but i don't understand how to use this (the comment above also do not help me understand what this is supposed to do and where to place it). Can you please give me an example? Also, what do you mean with "remove this conditional" - i never added a conditional?

The conditional is the lines I posted (pkgs/build-support/trivial-builders/test/default.nix lines 23-27) and is the broken code your change triggered (and those 4 lines should just be changed to one inherit references; line). Technically adding it to platforms just uncovered an existing bug elsewhere in nixpkgs, rather than your PR inherently being the problem, but updating those lines fixes eval with your PR

I just woke up and am on mobile, but I'll send a diff when I'm at a computer in a few hours to more clearly illustrate

[lilyinstarlight]

@tfc This diff should do it, but if you open a new PR, we'll watch ofborg to make sure it passes this time:

diff --git a/nixos/lib/testing/meta.nix b/nixos/lib/testing/meta.nix
index 529fe714fcf6..bdf313e5b119 100644
--- a/nixos/lib/testing/meta.nix
+++ b/nixos/lib/testing/meta.nix
@@ -36,7 +36,7 @@ in
           };
           platforms = lib.mkOption {
             type = types.listOf types.raw;
-            default = lib.platforms.linux;
+            default = lib.platforms.linux ++ lib.platforms.darwin;
             description = ''
               Sets the [`meta.platforms`](https://nixos.org/manual/nixpkgs/stable/#var-meta-platforms) attribute on the [{option}`test`](#test-opt-test) derivation.
             '';
diff --git a/pkgs/build-support/trivial-builders/test/default.nix b/pkgs/build-support/trivial-builders/test/default.nix
index f41372d922bb..e1ed0be72bf3 100644
--- a/pkgs/build-support/trivial-builders/test/default.nix
+++ b/pkgs/build-support/trivial-builders/test/default.nix
@@ -20,11 +20,7 @@ recurseIntoAttrs {
   concat = callPackage ./concat-test.nix {};
   linkFarm = callPackage ./link-farm.nix {};
   overriding = callPackage ../test-overriding.nix {};
-  # VM test not supported beyond linux yet
-  references =
-    if stdenv.hostPlatform.isLinux
-    then references
-    else {};
+  inherit references;
   writeCBin = callPackage ./writeCBin.nix {};
   writeClosure-union = callPackage ./writeClosure-union.nix {
     inherit (references) samples;

[tfc]

@lilyinstarlight Now i get the picture. Thank you very much, i will create a PR this afternoon.