From 2ad219c8aadb1666799d446bf66e1e863e473da4 Mon Sep 17 00:00:00 2001
From: Hraban Luyat <hraban@0brg.net>
Date: Sun, 30 Apr 2023 13:18:39 -0400
Subject: [PATCH] sbcl: explicitly document the cleanup convention

---
 pkgs/development/compilers/sbcl/2.x.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/development/compilers/sbcl/2.x.nix b/pkgs/development/compilers/sbcl/2.x.nix
index eee83a98b8e4..fa5382449cb5 100644
--- a/pkgs/development/compilers/sbcl/2.x.nix
+++ b/pkgs/development/compilers/sbcl/2.x.nix
@@ -19,6 +19,9 @@ let
       sha256 = "189gjqzdz10xh3ybiy4ch1r98bsmkcb4hpnrmggd4y2g5kqnyx4y";
     };
 
+    # The loosely held nixpkgs convention for SBCL is to keep the last two
+    # versions.
+    # https://github.com/NixOS/nixpkgs/pull/200994#issuecomment-1315042841
     "2.3.2" = {
       sha256 = "sha256-RMwWLPpjMqmojHoSHRkDiCikuk9r/7d+8cexdAfLHqo=";
     };