From b388850ca4cf925e67ca757f599202288cebad60 Mon Sep 17 00:00:00 2001
From: Alexandre Esteves <alexfmpe@proton.me>
Date: Mon, 2 Feb 2026 17:30:38 +0000
Subject: [PATCH] haskellPackages: fix eval cycle when doCheck is enabled for
 cross

---
 .../haskell-modules/configuration-nix.nix     | 29 +++++++++----------
 .../haskell-modules/configuration-windows.nix | 17 -----------
 2 files changed, 14 insertions(+), 32 deletions(-)

diff --git a/pkgs/development/haskell-modules/configuration-nix.nix b/pkgs/development/haskell-modules/configuration-nix.nix
index 0c3a8e40410b..221b4d2e30ef 100644
--- a/pkgs/development/haskell-modules/configuration-nix.nix
+++ b/pkgs/development/haskell-modules/configuration-nix.nix
@@ -2230,21 +2230,20 @@ builtins.intersectAttrs super {
 
   botan-bindings = super.botan-bindings.override { botan = pkgs.botan3; };
 
-  # Avoids a cycle by disabling use of the external interpreter for the packages that are dependencies of iserv-proxy.
-  # These in particular can't rely on template haskell for cross-compilation anyway as they can't rely on iserv-proxy.
-  inherit
-    (
-      let
-        noExternalInterpreter = overrideCabal {
-          enableExternalInterpreter = false;
-        };
-      in
-      lib.mapAttrs (_: noExternalInterpreter) { inherit (super) libiserv iserv-proxy network; }
-    )
-    libiserv
-    iserv-proxy
-    network
-    ;
+  iserv-proxy =
+    let
+      # Avoid a cycle by disabling tests and the external interpreter for packages that are dependencies of iserv-proxy.
+      # These in particular can't rely on template haskell for cross-compilation anyway as they can't rely on iserv-proxy.
+      # Also disable tests during iserv-proxy bootstrap since test packages tend to rely on TH for discovering test cases
+      breakExternalInterpreterBootstrapCycle = overrideCabal {
+        doCheck = false;
+        enableExternalInterpreter = false;
+      };
+      overlay = lib.mapAttrs (
+        _: pkg: if (pkg ? isHaskellLibrary) then breakExternalInterpreterBootstrapCycle pkg else pkg
+      );
+    in
+    super.iserv-proxy.overrideScope (_: overlay);
 
   # Workaround for flaky test: https://github.com/basvandijk/threads/issues/10
   threads = appendPatch ./patches/threads-flaky-test.patch super.threads;
diff --git a/pkgs/development/haskell-modules/configuration-windows.nix b/pkgs/development/haskell-modules/configuration-windows.nix
index 5489c415f09c..735a55ca4068 100644
--- a/pkgs/development/haskell-modules/configuration-windows.nix
+++ b/pkgs/development/haskell-modules/configuration-windows.nix
@@ -37,21 +37,4 @@ with haskellLib;
   # Root cause seems to be undefined references to libffi as shown by linking errors if we instead use "-Wl,--disable-auto-import"
   # See https://github.com/rust-lang/rust/issues/132226#issuecomment-2445100058
   iserv-proxy = appendConfigureFlag "--ghc-option=-optl=-Wl,--disable-runtime-pseudo-reloc" super.iserv-proxy;
-
-  # Avoids a cycle by disabling use of the external interpreter for the packages that are dependencies of iserv-proxy.
-  # See configuration-nix.nix, where iserv-proxy and network are handled.
-  # On Windows, network depends on temporary (see above), which depends on random, which depends on splitmix.
-  inherit
-    (
-      let
-        noExternalInterpreter = overrideCabal {
-          enableExternalInterpreter = false;
-        };
-      in
-      lib.mapAttrs (_: noExternalInterpreter) { inherit (super) random splitmix temporary; }
-    )
-    random
-    splitmix
-    temporary
-    ;
 })