From 0c0a8404e662bb6ed5533b560f2ad7542033207d Mon Sep 17 00:00:00 2001
From: leftibot <leftibot@users.noreply.github.com>
Date: Fri, 17 Apr 2026 08:15:41 -0600
Subject: [PATCH] Fix CI build: accommodate CMake 4.x and skip upstream chai
 REPL

The CI introduced in #34 surfaced two failures rooted in the outdated
CMakeLists.txt fetched as part of ChaiScript 6.1.0:

1. macOS runners ship CMake 4.x, which removes compatibility with
   cmake_minimum_required(VERSION < 3.5). The fetched subproject still
   declares VERSION 2.8 and configure aborts. Setting
   CMAKE_POLICY_VERSION_MINIMUM to 3.5 before add_subdirectory forces an
   acceptable floor for the transitive project.

2. Windows MSVC builds fail compiling ChaiScript's own src/main.cpp (the
   `chai` REPL) - a missing <chrono> include in upstream 6.1.0. The REPL
   target is unconditionally declared by the subproject, so adding
   EXCLUDE_FROM_ALL on add_subdirectory keeps it out of the default build.
   chaiscript_extras only needs ChaiScript's headers, so nothing else
   changes.

Also modernized: bump cmake_minimum_required to 3.16, drop the now-unused
BUILD_MODULES toggle, and explicitly opt into CMP0169 OLD so the
deprecated FetchContent_Populate call is kept quiet on CMake 3.30+.

Note: this PR does not address the unrelated ASAN/UBSAN heap-use-after-free
surfaced by string_methods_test - that is a runtime bug in the
extras+ChaiScript 6.1.0 interaction and will be tracked separately.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 CMakeLists.txt         |  2 +-
 cmake/chaiscript.cmake | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8bf1629..c125127 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.11) # FetchContent requires CMake 3.11
+cmake_minimum_required(VERSION 3.16)
 project(chaiscript_extras)
 
 # MINGW does not yet support C++11's concurrency features
diff --git a/cmake/chaiscript.cmake b/cmake/chaiscript.cmake
index 1d00c2e..8f16bf6 100644
--- a/cmake/chaiscript.cmake
+++ b/cmake/chaiscript.cmake
@@ -4,6 +4,14 @@ find_package(chaiscript ${CHAISCRIPT_VERSION} QUIET)
 if (NOT chaiscript_FOUND)
   include(FetchContent)
 
+  # FetchContent_Populate is deprecated in CMake 3.30+, but it still gives us the
+  # fine-grained control (EXCLUDE_FROM_ALL on add_subdirectory) we need to keep
+  # the upstream `chai` REPL target out of the default build. Opt into the OLD
+  # behaviour explicitly.
+  if(POLICY CMP0169)
+    cmake_policy(SET CMP0169 OLD)
+  endif()
+
   FetchContent_Declare(
     chaiscript
     GIT_REPOSITORY https://github.com/ChaiScript/ChaiScript.git
@@ -12,14 +20,21 @@ if (NOT chaiscript_FOUND)
 
   FetchContent_GetProperties(chaiscript)
   if (NOT chaiscript_POPULATED)
-    set(FETCHCONTENT_QUIET NO)
     FetchContent_Populate(chaiscript)
 
     set(BUILD_SAMPLES OFF CACHE BOOL "" FORCE)
-    set(BUILD_MODULES ON CACHE BOOL "" FORCE)
+    set(BUILD_MODULES OFF CACHE BOOL "" FORCE)
     set(BUILD_TESTING OFF CACHE BOOL "" FORCE)
     set(BUILD_LIBFUZZ_TESTER OFF CACHE BOOL "" FORCE)
 
-    add_subdirectory(${chaiscript_SOURCE_DIR} ${chaiscript_BINARY_DIR})
+    # ChaiScript 6.1.0's root CMakeLists.txt declares
+    # cmake_minimum_required(VERSION 2.8), which CMake 4.x refuses. Force a
+    # floor so the fetched subproject is accepted.
+    set(CMAKE_POLICY_VERSION_MINIMUM 3.5)
+
+    # EXCLUDE_FROM_ALL keeps ChaiScript's `chai` REPL out of the default build.
+    # We only consume ChaiScript's headers here, and its src/main.cpp in 6.1.0
+    # does not compile on current MSVC (missing <chrono> include).
+    add_subdirectory(${chaiscript_SOURCE_DIR} ${chaiscript_BINARY_DIR} EXCLUDE_FROM_ALL)
   endif()
 endif()