From 2fd0248e37614b52bf55c8ff3e3dc187262a603d Mon Sep 17 00:00:00 2001
From: Andreas Suter <andreas.suter@psi.ch>
Date: Tue, 25 Nov 2025 08:29:45 +0100
Subject: [PATCH] deal with Boost 1.89 not having system as component anymore.

---
 CMakeLists.txt                            | 18 +++++++++++++-----
 src/external/Nonlocal/prog/CMakeLists.txt | 18 +++++++++++++-----
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3947ca9f7..a07939f1b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -92,11 +92,19 @@ endif ()
 set(ROOT_GRTEQ_24 ${ROOT_GRTEQ_24} CACHE INTERNAL "ROOT Version check")
 
 #--- check for boost ----------------------------------------------------------
-find_package(Boost REQUIRED
-  COMPONENTS
-    system
-    filesystem
-)
+find_package(Boost QUIET)
+if (Boost_VERSION VERSION_GREATER_EQUAL "1.89")
+  find_package(Boost REQUIRED
+    COMPONENTS
+      filesystem
+  )
+else (Boost_VERSION VERSION_GREATER_EQUAL "1.89")
+  find_package(Boost REQUIRED
+    COMPONENTS
+      system
+      filesystem
+  )
+endif (Boost_VERSION VERSION_GREATER_EQUAL "1.89")
 message(STATUS "Boost libs: ${Boost_LIBRARIES}")
 
 #--- check for gsl ------------------------------------------------------------
diff --git a/src/external/Nonlocal/prog/CMakeLists.txt b/src/external/Nonlocal/prog/CMakeLists.txt
index f5213f075..1c36c0d05 100644
--- a/src/external/Nonlocal/prog/CMakeLists.txt
+++ b/src/external/Nonlocal/prog/CMakeLists.txt
@@ -22,11 +22,19 @@ if (ROOT_mathmore_FOUND)
 endif (ROOT_mathmore_FOUND)
 
 #--- check for boost ----------------------------------------------------------
-find_package(Boost REQUIRED
-  COMPONENTS
-    system
-    filesystem
-)
+find_package(Boost QUIET)
+if (Boost_VERSION VERSION_GREATER_EQUAL "1.89")
+  find_package(Boost REQUIRED
+    COMPONENTS
+      filesystem
+  )
+else (Boost_VERSION VERSION_GREATER_EQUAL "1.89")
+  find_package(Boost REQUIRED
+    COMPONENTS
+      system
+      filesystem
+  )
+endif (Boost_VERSION VERSION_GREATER_EQUAL "1.89")
 message(STATUS "Boost libs: ${Boost_LIBRARIES}")
 
 #--- check for fftw3 ----------------------------------------------------------