Improve package reproducibility

Packages using CMake often use file(GLOB ...) to retrieve a list of
source files. As this is based on readdir(), the resulting file list
is unsorted. A common use case is to pass this list directly to
add_executable or add_library. But as the order is unpredictable, the
binaries are not reproducible (because the order in which the objects
are linked will vary).

See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=824263

src/algorithms/observables/adapters/CMakeLists.txt

@@ -35,6 +35,7 @@ include_directories(
 )
 
 file(GLOB OBS_ADAPTER_HEADERS "*.h")
+list(SORT OBS_ADAPTER_HEADERS)
 add_library(obs_adapters ${OBS_ADAPTER_SOURCES} ${OBS_ADAPTER_HEADERS})
 source_group(Headers FILES ${OBS_ADAPTER_HEADERS})
 target_link_libraries(obs_adapters obs_gr_blocks ${GNURADIO_RUNTIME_LIBRARIES})

src/algorithms/observables/gnuradio_blocks/CMakeLists.txt

@@ -36,6 +36,7 @@ include_directories(
 )
 
 file(GLOB OBS_GR_BLOCKS_HEADERS "*.h")
+list(SORT OBS_GR_BLOCKS_HEADERS)
 add_library(obs_gr_blocks ${OBS_GR_BLOCKS_SOURCES} ${OBS_GR_BLOCKS_HEADERS})
 source_group(Headers FILES ${OBS_GR_BLOCKS_HEADERS})
 add_dependencies(obs_gr_blocks glog-${glog_RELEASE} armadillo-${armadillo_RELEASE})