From 04310494366312cd5c031cd82a6abd0d41b7cbc1 Mon Sep 17 00:00:00 2001
From: Sebastian Ehlert <28669218+awvwgk@users.noreply.github.com>
Date: Fri, 3 Sep 2021 19:23:34 +0200
Subject: [PATCH] Correctly set CMAKE_INSTALL_MODULEDIR cache variable

---
 config/CMakeLists.txt | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/config/CMakeLists.txt b/config/CMakeLists.txt
index 430cef2af..31b08e284 100644
--- a/config/CMakeLists.txt
+++ b/config/CMakeLists.txt
@@ -1,10 +1,14 @@
 # SPDX-Identifier: MIT
 
-option(
-  CMAKE_INSTALL_MODULEDIR
-  "Directory in prefix to install generated module files"
-  "${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}/${CMAKE_Fortran_COMPILER_ID}-${CMAKE_Fortran_COMPILER_VERSION}"
-)
+if(NOT DEFINED CMAKE_INSTALL_MODULEDIR)
+  set(
+    CMAKE_INSTALL_MODULEDIR
+    "${CMAKE_INSTALL_INCLUDEDIR}/${PROJECT_NAME}/${CMAKE_Fortran_COMPILER_ID}-${CMAKE_Fortran_COMPILER_VERSION}"
+    CACHE
+    STRING
+    "Directory in prefix to install generated module files"
+  )
+endif()
 
 # Export a pkg-config file
 configure_file(