From 65ebd6a17975ae513e27f981ad88b84a1fab1052 Mon Sep 17 00:00:00 2001
From: Ilya Fedin <fedin-ilja2010@ya.ru>
Date: Tue, 4 Feb 2020 05:26:52 +0400
Subject: [PATCH] Use system GSL since it's in the most common distributions

---
 external/gsl/CMakeLists.txt | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/external/gsl/CMakeLists.txt b/external/gsl/CMakeLists.txt
index c7a0883..aa8b09a 100644
--- a/external/gsl/CMakeLists.txt
+++ b/external/gsl/CMakeLists.txt
@@ -7,7 +7,15 @@
 add_library(external_gsl INTERFACE IMPORTED GLOBAL)
 add_library(desktop-app::external_gsl ALIAS external_gsl)
 
-target_include_directories(external_gsl SYSTEM
-INTERFACE
-    ${third_party_loc}/GSL/include
-)
+if (DESKTOP_APP_USE_PACKAGED)
+    find_path(GSL_INCLUDE_DIRS gsl/gsl)
+
+    if (NOT GSL_INCLUDE_DIRS)
+        message(FATAL_ERROR "Guidelines Support Library not found")
+    endif()
+else()
+    target_include_directories(external_gsl SYSTEM
+    INTERFACE
+        ${third_party_loc}/GSL/include
+    )
+endif()