diff --git a/Tests/CMakeTests/CheckSourceTreeTest.cmake.in b/Tests/CMakeTests/CheckSourceTreeTest.cmake.in
index 9150aef5b..73f8b013d 100644
--- a/Tests/CMakeTests/CheckSourceTreeTest.cmake.in
+++ b/Tests/CMakeTests/CheckSourceTreeTest.cmake.in
@@ -149,26 +149,77 @@ if(is_git_checkout AND NOT GIT_EXECUTABLE)
   # from it:
   #
   if(ctest_ini_file)
-    file(STRINGS "${ctest_ini_file}" lines REGEX "^GITCommand: (.*)$")
-    string(REGEX REPLACE "^GITCommand: (.*)$" "\\1" exe "${lines}")
+    file(STRINGS "${ctest_ini_file}" line REGEX "^GITCommand: (.*)$")
+    string(REGEX REPLACE "^GITCommand: (.*)$" "\\1" line "${line}")
+    if("${line}" MATCHES "^\"")
+      string(REGEX REPLACE "^\"([^\"]+)\" *.*$" "\\1" line "${line}")
+    else()
+      string(REGEX REPLACE "^([^ ]+) *.*$" "\\1" line "${line}")
+    endif()
+    set(exe "${line}")
     if("${exe}" STREQUAL "GITCOMMAND-NOTFOUND")
       set(exe "")
     endif()
+    if(exe)
+      message("info: GIT_EXECUTABLE set by 'GITCommand:' from '${ctest_ini_file}'")
+    endif()
 
     if(NOT exe)
-      file(STRINGS "${ctest_ini_file}" lines REGEX "^UpdateCommand: (.*)$")
-      string(REGEX REPLACE "^UpdateCommand: (.*)$" "\\1" exe "${lines}")
+      file(STRINGS "${ctest_ini_file}" line REGEX "^UpdateCommand: (.*)$")
+      string(REGEX REPLACE "^UpdateCommand: (.*)$" "\\1" line "${line}")
+      if("${line}" MATCHES "^\"")
+        string(REGEX REPLACE "^\"([^\"]+)\" *.*$" "\\1" line "${line}")
+      else()
+        string(REGEX REPLACE "^([^ ]+) *.*$" "\\1" line "${line}")
+      endif()
+      set(exe "${line}")
       if("${exe}" STREQUAL "GITCOMMAND-NOTFOUND")
         set(exe "")
       endif()
+      if(exe)
+        message("info: GIT_EXECUTABLE set by 'UpdateCommand:' from '${ctest_ini_file}'")
+      endif()
+    endif()
+  else()
+    message("info: no DartConfiguration.tcl or CTestConfiguration.ini file...")
+  endif()
+
+  # If we have still not grokked the exe, look in the Update.xml file to see
+  # if we can parse it from there...
+  #
+  if(NOT exe)
+    file(GLOB_RECURSE update_xml_file "${CMake_BINARY_DIR}/Testing/Update.xml")
+    if(update_xml_file)
+      file(STRINGS "${update_xml_file}" line
+        REGEX "^.*<UpdateCommand>(.*)</UpdateCommand>$" LIMIT_COUNT 1)
+      string(REPLACE "&quot\;" "\"" line "${line}")
+      string(REGEX REPLACE "^.*<UpdateCommand>(.*)</UpdateCommand>$" "\\1" line "${line}")
+      if("${line}" MATCHES "^\"")
+        string(REGEX REPLACE "^\"([^\"]+)\" *.*$" "\\1" line "${line}")
+      else()
+        string(REGEX REPLACE "^([^ ]+) *.*$" "\\1" line "${line}")
+      endif()
+      if(line)
+        set(exe "${line}")
+      endif()
+      if(exe)
+        message("info: GIT_EXECUTABLE set by '<UpdateCommand>' from '${update_xml_file}'")
+      endif()
+    else()
+      message("info: no Update.xml file...")
     endif()
   endif()
 
   if(exe)
     set(GIT_EXECUTABLE "${exe}")
-    message("info: set GIT_EXECUTABLE to '${GIT_EXECUTABLE}' based on '${ctest_ini_file}'")
+    message("GIT_EXECUTABLE='${GIT_EXECUTABLE}'")
+    message("")
+
+    if(NOT EXISTS "${GIT_EXECUTABLE}")
+      message(FATAL_ERROR "GIT_EXECUTABLE does not exist...")
+    endif()
   else()
-    message(FATAL_ERROR "could not determine GIT_EXECUTABLE based on '${ctest_ini_file}'...")
+    message(FATAL_ERROR "could not determine GIT_EXECUTABLE...")
   endif()
 endif()