From a5dec547193060c52c61591eb7d67099388260f4 Mon Sep 17 00:00:00 2001
From: Andrej730 <azhilenkov@gmail.com>
Date: Wed, 16 Sep 2026 13:56:45 +0500
Subject: [PATCH] cmake: add minimum required json version

---
 cmake/CMakeLists.txt          |  4 +++-
 cmake/Findnlohmann_json.cmake | 17 +++++++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index a269f5f0bc..ef6c3ac671 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -298,7 +298,9 @@ if(BUILD_IFCGEOM)
 endif()
 
 if(GLTF_SUPPORT)
-    find_package(nlohmann_json REQUIRED)
+    # 3.6.1 is the version currently used on the Windows build.
+    # 3.10.5 is the version shipped with Ubuntu 22.04.
+    find_package(nlohmann_json 3.6.1 REQUIRED)
 endif()
 
 # Add USD support to serializers
diff --git a/cmake/Findnlohmann_json.cmake b/cmake/Findnlohmann_json.cmake
index 172cb4a4f5..b3ac6d5b63 100644
--- a/cmake/Findnlohmann_json.cmake
+++ b/cmake/Findnlohmann_json.cmake
@@ -10,7 +10,7 @@
 UNIFY_ENVVARS_AND_CACHE(JSON_INCLUDE_DIR)
 
 if(NOT JSON_INCLUDE_DIR)
-    find_package(nlohmann_json CONFIG)
+    find_package(nlohmann_json ${nlohmann_json_FIND_VERSION} CONFIG)
     mark_as_advanced(nlohmann_json)
     if(nlohmann_json_DIR)
         return()
@@ -21,7 +21,20 @@ find_path(json_header_path "nlohmann/json.hpp" HINTS "${JSON_INCLUDE_DIR}")
 mark_as_advanced(json_header_path)
 
 if(json_header_path)
-    message(STATUS "JSON for Modern C++ header file found in '${json_header_path}'.")
+    file(STRINGS "${json_header_path}/nlohmann/json.hpp" json_version_major_line REGEX "^#define NLOHMANN_JSON_VERSION_MAJOR")
+    file(STRINGS "${json_header_path}/nlohmann/json.hpp" json_version_minor_line REGEX "^#define NLOHMANN_JSON_VERSION_MINOR")
+    file(STRINGS "${json_header_path}/nlohmann/json.hpp" json_version_patch_line REGEX "^#define NLOHMANN_JSON_VERSION_PATCH")
+    string(REGEX REPLACE "^#define NLOHMANN_JSON_VERSION_MAJOR ([0-9]+)$" "\\1" json_version_major "${json_version_major_line}")
+    string(REGEX REPLACE "^#define NLOHMANN_JSON_VERSION_MINOR ([0-9]+)$" "\\1" json_version_minor "${json_version_minor_line}")
+    string(REGEX REPLACE "^#define NLOHMANN_JSON_VERSION_PATCH ([0-9]+)$" "\\1" json_version_patch "${json_version_patch_line}")
+    set(nlohmann_json_VERSION "${json_version_major}.${json_version_minor}.${json_version_patch}")
+
+    include(FindPackageHandleStandardArgs)
+    find_package_handle_standard_args(nlohmann_json
+        REQUIRED_VARS json_header_path
+        VERSION_VAR nlohmann_json_VERSION
+    )
+
     add_library(nlohmann_json::nlohmann_json INTERFACE IMPORTED)
     target_include_directories(nlohmann_json::nlohmann_json INTERFACE ${json_header_path})
     return()