From 1b57774bdf4e6ccb84a5861cadfe8428680e28c3 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Mon, 24 Mar 2025 14:37:27 +0100
Subject: [PATCH] nix: make nix expressions forward-compatible with newer
 nixpkgs

When consuming PostgREST via flake, nixpkgs can be pinned to a newer
version, to which we might not be compatible, yet.
---
 nix/overlays/postgresql-libpq.nix | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/nix/overlays/postgresql-libpq.nix b/nix/overlays/postgresql-libpq.nix
index 2d1841e60..bace97da4 100644
--- a/nix/overlays/postgresql-libpq.nix
+++ b/nix/overlays/postgresql-libpq.nix
@@ -1,6 +1,7 @@
 _: super:
 {
-  libpq = super.callPackage ../libpq.nix {
+  # Depending on which nixpkgs version is pinned, libpq might either be available already - or not.
+  libpq = super.libpq or (super.callPackage ../libpq.nix {
     postgresql = super.postgresql_16;
-  };
+  });
 }