Restore cmake_uninstall.cmake.in using file(REMOVE).

Instead of execute_process. It's more portable long-term.

CMakeLists.txt

@@ -958,12 +958,12 @@ add_custom_target(distcheck DEPENDS dist
 
 # uninstall target
 configure_file(
-        "${CMAKE_SOURCE_DIR}/cmake/cmake_uninstall.sh.in"
-        "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.sh"
+        "${CMAKE_SOURCE_DIR}/cmake/cmake_uninstall.cmake.in"
+        "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
         @ONLY)
 
 add_custom_target(uninstall
-        COMMAND /bin/sh ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.sh)
+        COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
 
 set(_MODULES gnc-core-utils gnc-engine gnc-app-utils gnc-module gnc-locale-tax gnc-backend-xml-utils gnucash-guile)
 

cmake/CMakeLists.txt

@@ -11,7 +11,7 @@ endif()
 set_dist_list(cmake_DIST
   CMakeLists.txt
   README_CMAKE.txt
-  cmake_uninstall.sh.in
+  cmake_uninstall.cmake.in
   configure-appdata.cmake
   configure-gnucash-desktop.cmake
   configure-manpage.cmake

cmake/cmake_uninstall.cmake.in

@@ -0,0 +1,19 @@
+# This is taken from https://cmake.org/Wiki/CMake_FAQ#Can_I_do_.22make_uninstall.22_with_CMake.3F
+
+if(NOT EXISTS "@CMAKE_CURRENT_BINARY_DIR@/install_manifest.txt")
+  message(FATAL_ERROR "Cannot find install manifest: @CMAKE_CURRENT_BINARY_DIR@/install_manifest.txt")
+endif()
+
+file(READ "@CMAKE_CURRENT_BINARY_DIR@/install_manifest.txt" files)
+string(REGEX REPLACE "\n" ";" files "${files}")
+foreach(file ${files})
+  message(STATUS "Uninstalling $ENV{DESTDIR}${file}")
+  if(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+    file(REMOVE "$ENV{DESTDIR}${file}")
+    if(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+      message(FATAL_ERROR "Problem when removing $ENV{DESTDIR}${file}")
+    endif()
+  else()
+    message(STATUS "File $ENV{DESTDIR}${file} does not exist.")
+  endif()
+endforeach(file)