From ea3d37aec1813397cdf419fa57a9260d23a3f613 Mon Sep 17 00:00:00 2001
From: Pierre Roux <pierre.roux@onera.fr>
Date: Tue, 21 Apr 2026 09:19:16 +0200
Subject: [PATCH] coqPackages.interval: guard version check

Avoids nasty error when trying to get non existing intervals.
---
 pkgs/development/coq-modules/interval/default.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/coq-modules/interval/default.nix b/pkgs/development/coq-modules/interval/default.nix
index e7b4662f2c2b..8efe8b1f7589 100644
--- a/pkgs/development/coq-modules/interval/default.nix
+++ b/pkgs/development/coq-modules/interval/default.nix
@@ -65,7 +65,9 @@ mkCoqDerivation rec {
       mathcomp-boot
       mathcomp-fingroup
     ]
-    ++ lib.optionals (lib.versions.isGe "4.2.0" defaultVersion) [ gnuplot_qt ];
+    ++ lib.optionals (defaultVersion != null && lib.versions.isGe "4.2.0" defaultVersion) [
+      gnuplot_qt
+    ];
   useMelquiondRemake.logpath = "Interval";
   mlPlugin = true;