cmake: follow Debian soname convention for DEB package names

The runtime DEB package was named 'libkqueue' but Debian convention
requires the soversion suffix (e.g. 'libkqueue0'). This caused
dependency resolution failures when installing packages that depend
on 'libkqueue0'.

Extract the soversion into a KQUEUE_SOVERSION variable and use it
to construct CPACK_DEBIAN_MAIN_PACKAGE_NAME. Also fix the -dev
package dependency to reference the correct runtime package name.

Author: arr2036

CMakeLists.txt

@@ -266,7 +266,8 @@ if(ENABLE_SHARED)
   add_library(kqueue SHARED $<TARGET_OBJECTS:objlib>)
   # We should have absolute ABI compatibility between versions as none
   # of the public function signatures of variables will change.
-  set_target_properties(kqueue PROPERTIES SOVERSION 0)
+  set(KQUEUE_SOVERSION 0)
+  set_target_properties(kqueue PROPERTIES SOVERSION ${KQUEUE_SOVERSION})
 endif()
 if(ENABLE_STATIC)
   add_library(kqueue_static STATIC $<TARGET_OBJECTS:objlib>)
@@ -420,7 +421,9 @@ endif()
 #
 #  DEB Specific configuration
 #
-set(CPACK_DEBIAN_MAIN_PACKAGE_NAME "${CPACK_PACKAGE_NAME}")
+# Use soversion suffix for the runtime package name (e.g. libkqueue0)
+# to follow the Debian shared library packaging convention.
+set(CPACK_DEBIAN_MAIN_PACKAGE_NAME "${CPACK_PACKAGE_NAME}${KQUEUE_SOVERSION}")
 set(CPACK_DEBIAN_MAIN_PACKAGE_SECTION "libs")
 
 set(CPACK_DEBIAN_DEVEL_PACKAGE_NAME "${CPACK_PACKAGE_NAME}-dev")
@@ -437,10 +440,10 @@ set(CPACK_DEBIAN_PACKAGE_GENERATE_SHLIBS ON)
 #  library package is in sync with the headers.
 #
 if (PROJECT_VERSION_RELEASE)
-set(CPACK_DEBIAN_DEVEL_PACKAGE_DEPENDS "${CPACK_PACKAGE_NAME} (= ${PROJECT_VERSION}-${PROJECT_VERSION_RELEASE})")
+set(CPACK_DEBIAN_DEVEL_PACKAGE_DEPENDS "${CPACK_DEBIAN_MAIN_PACKAGE_NAME} (= ${PROJECT_VERSION}-${PROJECT_VERSION_RELEASE})")
 set(CPACK_DEBIAN_PACKAGE_RELEASE ${PROJECT_VERSION_RELEASE})
 else()
-set(CPACK_DEBIAN_DEVEL_PACKAGE_DEPENDS "${CPACK_PACKAGE_NAME} (= ${PROJECT_VERSION})")
+set(CPACK_DEBIAN_DEVEL_PACKAGE_DEPENDS "${CPACK_DEBIAN_MAIN_PACKAGE_NAME} (= ${PROJECT_VERSION})")
 endif()
 
 set(CPACK_SOURCE_PACKAGE_FILE_NAME "${CPACK_PACKAGE_NAME}-${PROJECT_VERSION}")