Index: /issm/trunk-jpl/src/m/solve/waitonlock.py
===================================================================
--- /issm/trunk-jpl/src/m/solve/waitonlock.py	(revision 26346)
+++ /issm/trunk-jpl/src/m/solve/waitonlock.py	(revision 26347)
@@ -74,7 +74,8 @@
             outs, errs = subproc.communicate() # NOTE: Need to consume output before checking return code
             # TODO: Debug the following check under Linux (exits after first iteration with errs = "b")
+            # UPDATE: Works in testing under Debian Linux system. Leaving comment for now so that it is easier to backtrace this issue if someone else encounters it.
             #
-            # if errs != '':
-            #     raise Exception("waitonlock: check for existence of files failed: {}".format(errs))
+            if errs != '':
+                raise Exception("waitonlock: check for existence of files failed: {}".format(errs))
             ispresent = not subproc.returncode
             if ispresent: