From 7a35667a1c0d9e2df7ce0a60d44b81ded92a996d Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Sun, 23 Mar 2025 16:43:00 +0100
Subject: [PATCH] postgresql: simplify doInstallCheck condition and fix
 comments

---
 pkgs/servers/sql/postgresql/generic.nix | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/pkgs/servers/sql/postgresql/generic.nix b/pkgs/servers/sql/postgresql/generic.nix
index 52c6e9a7d7e7..e07b6c2616a3 100644
--- a/pkgs/servers/sql/postgresql/generic.nix
+++ b/pkgs/servers/sql/postgresql/generic.nix
@@ -395,12 +395,15 @@ let
       doInstallCheck =
         !(stdenv'.hostPlatform.isStatic)
         &&
-          # Tests just get stuck on macOS 14.x for v13 and v14
-          !(stdenv'.hostPlatform.isDarwin && olderThan "15")
-        &&
-          # x86: Likely due to rosetta emulation:
+          # Tests currently can't be run on darwin, because of a Nix bug:
+          # https://github.com/NixOS/nix/issues/12548
+          # https://git.lix.systems/lix-project/lix/issues/691
+          # The error appears as this in the initdb logs:
           #   FATAL:  could not create shared memory segment: Cannot allocate memory
-          # aarch64: not sure why, e.g. https://hydra.nixos.org/build/292573408/nixlog/7
+          # Don't let yourself be fooled when trying to remove this condition: Running
+          # the tests works fine most of the time. But once the tests (or any package using
+          # postgresqlTestHook) fails on the same machine for a few times, enough IPC objects
+          # will be stuck around, and any future builds with the tests enabled *will* fail.
           !(stdenv'.hostPlatform.isDarwin);
       installCheckTarget = "check-world";