stdenv: Fix handleEvalIssue for error problems (#496156)

pkgs/stdenv/generic/check-meta.nix

@@ -662,7 +662,13 @@ let
               "Refusing to evaluate package '${getNameWithVersion attrs}' in ${pos_str meta} because it ${error.msg}"
               + lib.optionalString (!inHydra && error.remediation != "") "\n${error.remediation}";
           in
-          if config ? handleEvalIssue then config.handleEvalIssue error.reason msg else throw msg;
+          if config ? handleEvalIssue then
+            if error.reason == "problem" then
+              error.handleProblem config.handleEvalIssue
+            else
+              config.handleEvalIssue error.reason msg
+          else
+            throw msg;
 
       giveWarning =
         acc: warning:

pkgs/stdenv/generic/problems.nix

@@ -485,6 +485,11 @@ rec {
           null
         else
           {
+            reason = "problem";
+            # Only there for PR CI evaluation
+            handleProblem =
+              handleEvalIssue:
+              lib.foldl' (result: problem: handleEvalIssue problem.kind (fullMessage problem)) true errorProblems;
             msg = ''
               has problems:
               ${concatMapStringsSep "\n" (x: "- ${fullMessage x}") errorProblems}

pkgs/test/problems/cases/handleEvalIssue/default.nix

@@ -0,0 +1,30 @@
+{
+  nixpkgs ? ../../../../..,
+}:
+let
+  pkgs = import nixpkgs {
+    system = "x86_64-linux";
+    overlays = [ ];
+    config = {
+      checkMeta = true;
+      handleEvalIssue = reason: errormsg: builtins.trace "reason: ${reason}, errormsg: ${errormsg}" true;
+      problems.matchers = [
+        {
+          kind = "deprecated";
+          handler = "error";
+        }
+        {
+          kind = "removal";
+          handler = "error";
+        }
+      ];
+    };
+  };
+in
+pkgs.stdenvNoCC.mkDerivation {
+  pname = "a";
+  version = "0";
+  meta.description = "Some package";
+  meta.problems.removal.message = "To be removed.";
+  meta.problems.deprecated.message = "To be deprecated.";
+}

pkgs/test/problems/cases/handleEvalIssue/expected-stderr

@@ -0,0 +1,3 @@
+trace: reason: deprecated, errormsg: deprecated: To be deprecated.
+trace: reason: removal, errormsg: removal: To be removed.
+warning: you did not specify '--add-root'; the result might be removed by the garbage collector