···11+diff --git a/CMakeLists.txt b/CMakeLists.txt
22+--- a/CMakeLists.txt
33++++ b/CMakeLists.txt
44+@@ -37,21 +37,6 @@ message(STATUS "default momentum and length are ${HEPMC_DEFAULT_MOM_UNIT} ${HEPM
55+ # find the HepMC cmake modules
66+ set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules ${CMAKE_MODULE_PATH})
77+88+-# make sure we are not building from within the source code directory
99+-string(COMPARE EQUAL "${CMAKE_SOURCE_DIR}" "${CMAKE_BINARY_DIR}" in_source)
1010+-string( REGEX MATCH "${CMAKE_SOURCE_DIR}/" in_source_subdir
1111+-"${CMAKE_BINARY_DIR}")
1212+-if (in_source OR in_source_subdir)
1313+- message(FATAL_ERROR "
1414+-ERROR: In source builds of this project are not allowed.
1515+-A separate build directory is required.
1616+-Please create one and run cmake from the build directory.
1717+-Also note that cmake has just added files to your source code directory.
1818+-We suggest getting a new copy of the source code.
1919+-Otherwise, delete `CMakeCache.txt' and the directory `CMakeFiles'.
2020+- ")
2121+-endif ()
2222+-
2323+ # build_docs is OFF (false) by default
2424+ if ( build_docs )
2525+ message(STATUS "documents WILL be built and installed" )