From 932b3cabda1023d877fd9298280e2b344e3d4446 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Sat, 11 Sep 2021 06:05:29 -0400
Subject: [PATCH] add missing include (since we not longer include GTest.cmake)

---
 unittest/commands/CMakeLists.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/unittest/commands/CMakeLists.txt b/unittest/commands/CMakeLists.txt
index 28c2cc084f..8891647911 100644
--- a/unittest/commands/CMakeLists.txt
+++ b/unittest/commands/CMakeLists.txt
@@ -1,6 +1,7 @@
 
 # build LAMMPS plugins, but not on Windows
 if((NOT (CMAKE_SYSTEM_NAME STREQUAL "Windows")) AND PKG_PLUGIN)
+  include(ExternalProject)
   ExternalProject_Add(plugins
                       SOURCE_DIR      "${LAMMPS_DIR}/examples/plugins"
                       BINARY_DIR      ${CMAKE_BINARY_DIR}/build-plugins