From b250237e015f7ffb78d576f8192224afac052135 Mon Sep 17 00:00:00 2001
From: Luca Matei Pintilie <luca@lucamatei.com>
Date: Sat, 10 Jan 2026 23:04:36 +0100
Subject: [PATCH] install files using GNUInstallDirs

---
 CMakeLists.txt | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 96854c0..687a442 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -344,11 +344,23 @@ add_custom_target(everything DEPENDS test_suite biboumi)
 #
 ## Install target
 #
-install(TARGETS ${PROJECT_NAME} RUNTIME                     DESTINATION bin)
-install(FILES   ${CMAKE_CURRENT_BINARY_DIR}/man/biboumi.1   DESTINATION share/man/man1         OPTIONAL COMPONENT documentation)
-install(FILES   ${CMAKE_CURRENT_BINARY_DIR}/biboumi.service DESTINATION lib/systemd/system     COMPONENT init)
+include(GNUInstallDirs)
+
+# From cmake version 4.1 CMAKE_INSTALL_SYSCONFDIR has special behaviour when
+# CMAKE_INSTALL_PREFIX is /, /usr, or /opt/..., so to not update cmake version
+# just yet reimplement this here
+# https://cmake.org/cmake/help/latest/module/GNUInstallDirs.html#special-cases
+if (CMAKE_INSTALL_SYSCONFDIR STREQUAL "etc" AND (CMAKE_INSTALL_PREFIX STREQUAL "/" OR CMAKE_INSTALL_PREFIX STREQUAL "/usr"))
+	set(CMAKE_INSTALL_SYSCONFDIR "/etc")
+elseif (CMAKE_INSTALL_SYSCONFDIR STREQUAL "etc" AND (CMAKE_INSTALL_PREFIX MATCHES "^/opt/"))
+	set(CMAKE_INSTALL_SYSCONFDIR "/etc${CMAKE_INSTALL_PREFIX}")
+endif()
+
+install(TARGETS ${PROJECT_NAME} RUNTIME                     DESTINATION ${CMAKE_INSTALL_BINDIR})
+install(FILES   ${CMAKE_CURRENT_BINARY_DIR}/man/biboumi.1   DESTINATION ${CMAKE_INSTALL_MANDIR}/man1         OPTIONAL COMPONENT documentation)
+install(FILES   ${CMAKE_CURRENT_BINARY_DIR}/biboumi.service DESTINATION ${CMAKE_INSTALL_LIBDIR}/systemd/system     COMPONENT init)
 file(GLOB policy_files conf/*policy.txt)
-install(FILES   ${policy_files}                             DESTINATION etc/biboumi           COMPONENT configuration)
+install(FILES   ${policy_files}                             DESTINATION ${CMAKE_INSTALL_SYSCONFDIR}/biboumi           COMPONENT configuration)
 
 #
 ## Dist target