- add -lexecinfo because LDFLAGS passed from outside somehow gets lost

--- test/unittest/CMakeLists.txt.orig	2023-09-15 04:25:30 UTC
+++ test/unittest/CMakeLists.txt
@@ -9,6 +9,8 @@ if (UNIX)
   SET(CMAKE_EXE_LINKER_FLAGS "-pthread")
 endif(UNIX)
 
+SET(CMAKE_EXE_LINKER_FLAGS "-lexecinfo")
+
 # Compiler definitions needed to use GNU/POSIX extensions
 set(ENABLE_GNU_EXTENSION_FLAGS -D_XOPEN_SOURCE=700
   -D_POSIX_SOURCE -D_POSIX_C_SOURCE=200809L -D_DARWIN_C_SOURCE)