https://github.com/spring/spring/commit/a385d9d7715a

CMake Error at /usr/local/share/cmake/Modules/FindBoost.cmake:2049 (message):
  Unable to find the requested Boost libraries.

  Boost version: 1.69.0

  Boost include path: /usr/local/include

  Could not find the following Boost libraries:

          boost_signals

  Some (but not all) of the required Boost libraries were found.  You may
  need to install these additional Boost libraries.  Alternatively, set
  BOOST_LIBRARYDIR to the directory containing Boost libraries or BOOST_ROOT
  to the location of Boost.
Call Stack (most recent call first):
  CMakeLists.txt:245 (FIND_PACKAGE)

--- CMakeLists.txt.orig	2014-10-07 20:09:51 UTC
+++ CMakeLists.txt
@@ -242,7 +242,7 @@ if    (MINGW)
 	set(SDL2_INCLUDE_DIR "${MINGWLIBS}/include/SDL2")
 endif (MINGW)
 
-FIND_PACKAGE(Boost 1.47.0 COMPONENTS thread regex program_options system chrono signals filesystem REQUIRED)
+FIND_PACKAGE(Boost 1.47.0 COMPONENTS thread regex program_options system chrono filesystem REQUIRED)
 FIND_PACKAGE(Boost 1.47.0 COMPONENTS timer)
 INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIR})