From 73589b4e56400e9a91fca0f9a036446fe6966899 Mon Sep 17 00:00:00 2001
From: Martin Joerg <martin.joerg@gmail.com>
Date: Fri, 28 Nov 2025 13:59:16 +0000
Subject: [PATCH] python3Packages.graph-tool: enable graphviz support

---
 pkgs/development/python-modules/graph-tool/default.nix | 9 +++++++++
 pkgs/top-level/python-packages.nix                     | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/python-modules/graph-tool/default.nix b/pkgs/development/python-modules/graph-tool/default.nix
index cf4b067f31d8..f455258ea14b 100644
--- a/pkgs/development/python-modules/graph-tool/default.nix
+++ b/pkgs/development/python-modules/graph-tool/default.nix
@@ -11,6 +11,7 @@
   expat,
   fontconfig,
   gobject-introspection,
+  graphviz,
   gtk3,
   llvmPackages,
   matplotlib,
@@ -58,6 +59,14 @@ buildPythonPackage rec {
       substituteInPlace configure \
         --replace-fail 'tput setaf $1' : \
         --replace-fail 'tput sgr0' :
+    ''
+    +
+    # hardcode path to graphviz library to avoid find_library, which would require setting LD_LIBRARY_PATH
+    ''
+      substituteInPlace src/graph_tool/draw/graphviz_draw.py \
+        --replace-fail \
+          'ctypes.util.find_library("gvc")' \
+          '"${lib.getLib graphviz}/lib/libgvc${stdenv.hostPlatform.extensions.sharedLibrary}"'
     '';
 
   configureFlags =
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index c83b9dde6d46..52da08753cf9 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -6422,7 +6422,7 @@ self: super: with self; {
 
   granian = callPackage ../development/python-modules/granian { };
 
-  graph-tool = callPackage ../development/python-modules/graph-tool { inherit (pkgs) cgal; };
+  graph-tool = callPackage ../development/python-modules/graph-tool { inherit (pkgs) cgal graphviz; };
 
   grapheme = callPackage ../development/python-modules/grapheme { };