no member named 'construct' in 'optional<type-parameter-0-0 &>' error in with Clang 19

[afarber]

Issue

When updating the file docker/Dockerfile-alpine alpine:3.20.5 -> alpine:3.21.2

Then these 2 programs are updated as can be seen in the "docker build" (attached):

Clang 17.0.6 -> Clang 19.1.4
cmake 3.29.3 -> cmake 3.31.1

And the following warning and error can be seen:

#10 5.460 CMake Warning (dev) at CMakeLists.txt:403 (find_package):
#10 5.460   Policy CMP0167 is not set: The FindBoost module is removed.  Run "cmake
#10 5.460   --help-policy CMP0167" for policy details.  Use the cmake_policy command to
#10 5.460   set the policy and suppress this warning.
#10 5.460
#10 5.460 This warning is for project developers.  Use -Wno-dev to suppress it.

#10 189.5 In file included from /src/src/extractor/scripting_environment_lua.cpp:1:
#10 189.5 In file included from /src/include/extractor/scripting_environment_lua.hpp:15:
#10 189.5 /src/third_party/sol2/include/sol/sol.hpp:6755:10: error: no member named 'construct' in 'optional<type-parameter-0-0 &>'
#10 189.5  6755 |                         this->construct(std::forward<Args>(args)...);
#10 189.5       |                         ~~~~  ^

Steps to reproduce

Just change to alpine:3.21.2 in docker/Dockerfile-alpine and run:

docker build -f docker/Dockerfile-alpine --build-arg BUILD_CONCURRENCY=4 --build-arg DOCKER_TAG=tag222 --tag tag2 --memory=16g .

Fix

Please do not close this issue, I will submit a fix in few minutes based on these 2 webpages:

Fix for emplace compile error: ThePhD/sol2@d805d02
Fix for cmake warning: https://cmake.org/cmake/help/latest/policy/CMP0167.html

Logfiles

alpine-3.21.2-BROKEN.txt
alpine-3.21.2-FIXED.txt