LuaJIT: Fix WITH_AMALG option failing during parallel builds
Addresses the "'fold_hash' undeclared" compile errors in
See also
@@ -306,6 +306,15 @@ IF(WIN32)
ELSE()
IF(WITH_AMALG)
add_executable(luajit ${LUAJIT_DIR}/src/luajit.c ${LUAJIT_DIR}/src/ljamalg.c ${DEPS})
+ # When using WITH_AMALG during a parallel build, its possible to run into
+ # false-positive "error: 'fold_hash' undeclared" compile errors due to a weird interaction
+ # when building two ljamalg.c at the same time.
+ #
+ # This adds a fake dependency from one to the other, forcing the build process to
+ # compile them sequentially rather than parallel.
+ #
+ # See https://github.com/torch/luajit-rocks/issues/39
+ add_dependencies(luajit luajit-5.1)
ELSE()
add_executable(luajit ${LUAJIT_DIR}/src/luajit.c ${SRC_LJCORE} ${DEPS})
ENDIF()
