Lots of changes in cmake config need to be done - this is just a very rough...

--- a/SofaKernel/cmake/Modules/FindThreads.cmake

+++ b/SofaKernel/cmake/Modules/FindThreads.cmake

@@ -125,36 +125,12 @@ ELSE()

         # We have pthread.h

         # Let's check for the library now.

         #

-        SET(CMAKE_HAVE_THREADS_LIBRARY)

-        IF(NOT THREADS_HAVE_PTHREAD_ARG)

-

-            # Do we have -lpthreads

-            CHECK_LIBRARY_EXISTS(pthreads pthread_create "" CMAKE_HAVE_PTHREADS_CREATE)

-            IF(CMAKE_HAVE_PTHREADS_CREATE)

-                SET(CMAKE_THREAD_LIBS_INIT "-lpthreads")

-                SET(CMAKE_HAVE_THREADS_LIBRARY 1)

-                SET(Threads_FOUND TRUE)

-            ENDIF()

-

-            # Ok, how about -lpthread

-            CHECK_LIBRARY_EXISTS(pthread pthread_create "" CMAKE_HAVE_PTHREAD_CREATE)

-            IF(CMAKE_HAVE_PTHREAD_CREATE)

-                SET(CMAKE_THREAD_LIBS_INIT "-lpthread")

-                SET(Threads_FOUND TRUE)

-                SET(CMAKE_HAVE_THREADS_LIBRARY 1)

-            ENDIF()

+	# --> https://stackoverflow.com/questions/1620918/cmake-and-libpthread

+	set(THREADS_PREFER_PTHREAD_FLAG ON)

+	find_package(Threads REQUIRED)

+	# target_link_libraries(my_app Threads::Threads)

-            IF(CMAKE_SYSTEM MATCHES "SunOS.*")

-                # On sun also check for -lthread

-                CHECK_LIBRARY_EXISTS(thread thr_create "" CMAKE_HAVE_THR_CREATE)

-                IF(CMAKE_HAVE_THR_CREATE)

-                    SET(CMAKE_THREAD_LIBS_INIT "-lthread")

-                    SET(CMAKE_HAVE_THREADS_LIBRARY 1)

-                    SET(Threads_FOUND TRUE)

-                ENDIF()

-            ENDIF(CMAKE_SYSTEM MATCHES "SunOS.*")

-

-        ENDIF(NOT THREADS_HAVE_PTHREAD_ARG)

+        SET(CMAKE_HAVE_THREADS_LIBRARY)

         IF(NOT CMAKE_HAVE_THREADS_LIBRARY)

             # If we did not found -lpthread, -lpthread, or -lthread, look for -pthread

pthreads.patch

use_debian_packaged_libs.patch

--- a/CMakeLists.txt

+++ b/CMakeLists.txt

@@ -138,7 +138,6 @@ option(SOFA_BUILD_TESTS "Compile the aut

@@ -158,7 +158,6 @@ option(SOFA_BUILD_TESTS "Compile the aut

 if(SOFA_BUILD_TESTS)

     # Enable testing features of cmake, like the add_test() command.

     enable_testing()

 ## Active or not the use of ccache

--- a/extlibs/CMakeLists.txt

+++ b/extlibs/CMakeLists.txt

@@ -1,24 +1,10 @@

@@ -1,33 +1,5 @@

 cmake_minimum_required(VERSION 3.1)

-set(EXTLIBS_TARGETS

-    tinyxml

-)

-

 ## Necessary ones

-add_subdirectory(SuiteSparse)

-add_subdirectory(csparse)

-add_subdirectory(${SOFA_KERNEL_SOURCE_DIR}/extlibs/eigen-3.2.7 eigen)

-######## SofaKernel/extlibs ########

-

-# Eigen (header-only): see SofaKernel/cmake/Modules/FindEigen3.cmake

-set(EIGEN_ROOT "${SOFA_KERNEL_SOURCE_DIR}/extlibs/eigen-3.2.7" CACHE PATH "Eigen directory (containing Eigen/src/...)")

-mark_as_advanced(EIGEN_ROOT)

-

-# Nlohmann JSON (header-only): see SofaKernel/cmake/Modules/FindJson.cmake

-set(JSON_ROOT "${SOFA_KERNEL_SOURCE_DIR}/extlibs/json" CACHE PATH "Nlohmann JSON directory")

-mark_as_advanced(JSON_ROOT)

-

-# Newmat

-find_package(Newmat QUIET)

-if(NOT Newmat_FOUND)

-    add_subdirectory(${SOFA_KERNEL_SOURCE_DIR}/extlibs/newmat newmat)

-endif()

-

-# TinyXML

-find_package(TinyXML QUIET)

-if(NOT TinyXML_FOUND)

-    add_subdirectory(${SOFA_KERNEL_SOURCE_DIR}/extlibs/tinyxml tinyxml)

-add_subdirectory(${SOFA_KERNEL_SOURCE_DIR}/extlibs/json json)

-endif()

-

 ####################################

 ## Optional ones

 if (SOFAGUI_ENABLE_QWT)

     message("Qwt activated")

-    add_subdirectory(qwt-6.1.2/src qwt)

 endif()

 option(SOFA_BUILD_MINIFLOWVR "Build the miniFlowVR library distributed in the extlibs/ directory." OFF)

 ## Necessary ones