From 18e441f8ec396baa531b39a4907824cc75f701a1 Mon Sep 17 00:00:00 2001
From: Matthias Maier <tamiko@43-1.org>
Date: Wed, 13 May 2020 17:54:10 -0500
Subject: [PATCH] CMake: relax arpack and parpack library directory
 requirements

Some Linux distributions install the parallel libparpack.so* component
in an MPI vendor specific directory different from the location of the
serial libarpack.so* library. We can thus not assume that both are
located in the same directory.

Closes: #10197
---
 cmake/modules/FindARPACK.cmake | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/cmake/modules/FindARPACK.cmake b/cmake/modules/FindARPACK.cmake
index 21c1466b62..b5cad285ed 100644
--- a/cmake/modules/FindARPACK.cmake
+++ b/cmake/modules/FindARPACK.cmake
@@ -26,6 +26,9 @@
 SET(ARPACK_DIR "" CACHE PATH "An optional hint to an ARPACK installation")
 SET_IF_EMPTY(ARPACK_DIR "$ENV{ARPACK_DIR}")
 
+SET(PARPACK_DIR "" CACHE PATH "An optional hint to a PARPACK installation")
+SET_IF_EMPTY(PARPACK_DIR "$ENV{PARPACK_DIR}")
+
 DEAL_II_FIND_LIBRARY(ARPACK_LIBRARY
   NAMES arpack
   HINTS ${ARPACK_DIR}
@@ -33,20 +36,11 @@ DEAL_II_FIND_LIBRARY(ARPACK_LIBRARY
   )
 
 IF(DEAL_II_WITH_MPI)
-  #
-  # Sanity check: Only search the parpack library in the same directory as
-  # the arpack library...
-  #
   GET_FILENAME_COMPONENT(_path "${ARPACK_LIBRARY}" PATH)
   DEAL_II_FIND_LIBRARY(PARPACK_LIBRARY
     NAMES parpack
-    HINTS ${_path}
-    NO_DEFAULT_PATH
-    NO_CMAKE_ENVIRONMENT_PATH
-    NO_CMAKE_PATH
-    NO_SYSTEM_ENVIRONMENT_PATH
-    NO_CMAKE_SYSTEM_PATH
-    NO_CMAKE_FIND_ROOT_PATH
+    HINTS ${_path} ${ARPACK_DIR} ${PARPACK_DIR}
+    PATH_SUFFIXES lib${LIB_SUFFIX} lib64 lib
     )
 ELSE()
   SET(PARPACK_LIBRARY "PARPACK_LIBRARY-NOTFOUND")
-- 
2.39.5