From 1e171e5c08b8d244e2180a107401bbfde58d382e Mon Sep 17 00:00:00 2001
From: Jose Luis Blanco-Claraco <joseluisblancoc@gmail.com>
Date: Sat, 27 Jul 2024 02:13:37 +0200
Subject: [PATCH] handle external deps in apps too

---
 3rdparty/wxThings/CMakeLists.txt          |  1 +
 cmakemodules/DeclareAppDependencies.cmake | 11 +++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/3rdparty/wxThings/CMakeLists.txt b/3rdparty/wxThings/CMakeLists.txt
index bb25666f7f..1ec2c688d0 100644
--- a/3rdparty/wxThings/CMakeLists.txt
+++ b/3rdparty/wxThings/CMakeLists.txt
@@ -20,3 +20,4 @@ target_include_directories(
 	"${MRPT_SOURCE_DIR}/3rdparty/wxThings/"
 	)
 target_link_libraries(mrptwxthings PRIVATE imp_wxwidgets)
+
diff --git a/cmakemodules/DeclareAppDependencies.cmake b/cmakemodules/DeclareAppDependencies.cmake
index 17446c6b9d..8d54dec7f1 100644
--- a/cmakemodules/DeclareAppDependencies.cmake
+++ b/cmakemodules/DeclareAppDependencies.cmake
@@ -31,9 +31,16 @@ macro(DeclareAppDependencies name)
 	foreach (_DEP ${ALL_DEPS})
 		# Check if all dependencies are to be build:
 		string(REGEX REPLACE "mrpt::(.*)" "\\1" DEP_MRPT_NAME ${_DEP})
+
 		if ("${BUILD_mrpt-${DEP_MRPT_NAME}}" STREQUAL "OFF")
-			set(AUX_ALL_DEPS_BUILD 0)
-			message(STATUS "*Warning*: App ${name} cannot be built because dependency mrpt-${DEP_MRPT_NAME} has been disabled!")
+			# Attempt at using system version?
+			find_package(mrpt-${DEP_MRPT_NAME})
+			if (NOT TARGET mrpt::${DEP_MRPT_NAME})
+				set(AUX_ALL_DEPS_BUILD 0)
+				message(STATUS "*Warning*: App ${name} cannot be built because dependency mrpt-${DEP_MRPT_NAME} has been disabled!")
+			else()
+				message(STATUS "*Warning*: App ${name} is using system depency: mrpt-${DEP_MRPT_NAME}")
+			endif()
 		endif()
 	endforeach()