$NetBSD$

Add support for NetBSD.

--- ext/process/CMakeLists.txt.orig	2019-06-09 21:33:58.000000000 +0000
+++ ext/process/CMakeLists.txt
@@ -16,6 +16,8 @@ ELSEIF(CMAKE_SYSTEM_NAME STREQUAL "Linux
   # For shm_open, shm_unlink
   # NB FreeBSD has it on libc
   TARGET_LINK_LIBRARIES(sagittarius--process rt)
+ELSEIF(CMAKE_SYSTEM_NAME STREQUAL "NetBSD")
+  TARGET_LINK_LIBRARIES(sagittarius--process rt)
 ENDIF()
 
 
@@ -39,6 +41,9 @@ IF(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   # NB FreeBSD has it on libc
   TARGET_LINK_LIBRARIES(test-shm rt)
   TARGET_LINK_LIBRARIES(test-sem rt pthread)
+ELSEIF(CMAKE_SYSTEM_NAME STREQUAL "NetBSD")
+  TARGET_LINK_LIBRARIES(test-shm rt)
+  TARGET_LINK_LIBRARIES(test-sem rt pthread)
 ELSEIF (${SAGITTARIUS_PLATFORM} MATCHES ".*bsd" 
     OR ${SAGITTARIUS_OS} STREQUAL "qnx")
   TARGET_LINK_LIBRARIES(test-shm c)