CMake: Properly handle Udev missing

When udev is not available, the variables for libraries and
include paths are set to NOTFOUND rather than an empty string
and CMake exits with an error. Use a generator expression to
only use these variables when UDEV_FOUND is true.

1 files changed, 2 insertions, 2 deletions

diff --git a/apt-pkg/CMakeLists.txt b/apt-pkg/CMakeLists.txt
index 651e55c79..2f5ad3200 100644
--- a/apt-pkg/CMakeLists.txt
+++ b/apt-pkg/CMakeLists.txt
@@ -44,7 +44,7 @@ target_include_directories(apt-pkg
                                    ${BZIP2_INCLUDE_DIR}
                                    ${LZMA_INCLUDE_DIRS}
                                    ${LZ4_INCLUDE_DIRS}
-                                   ${UDEV_INCLUDE_DIRS}
+                                   $<$<BOOL:${UDEV_FOUND}>:${UDEV_INCLUDE_DIRS}>
                                    ${ICONV_INCLUDE_DIRS}
 )
 
@@ -55,7 +55,7 @@ target_link_libraries(apt-pkg
                              ${BZIP2_LIBRARIES}
                              ${LZMA_LIBRARIES}
                              ${LZ4_LIBRARIES}
-                             ${UDEV_LIBRARIES}
+                             $<$<BOOL:${UDEV_FOUND}>:${UDEV_LIBRARIES}>
                              ${ICONV_LIBRARIES}
 )
 set_target_properties(apt-pkg PROPERTIES VERSION ${MAJOR}.${MINOR})