Oh come on Python.

src/modules/umount/main.py

@@ -49,11 +49,14 @@ def run():
     :return:
     """
     root_mount_point = libcalamares.globalstorage.value("rootMountPoint")
-    log_source = libcalamares.job.configuration["srcLog"]
-    log_destination = libcalamares.job.configuration["destLog"]
 
-    # copy installation log before umount
-    if(log_source):
+    if(libcalamares.job.configuration and
+    libcalamares.job.configuration["srcLog"] and
+    libcalamares.job.configuration["destLog"]):
+        log_source = libcalamares.job.configuration["srcLog"]
+        log_destination = libcalamares.job.configuration["destLog"]
+
+        # copy installation log before umount
         if(os.path.exists('{!s}'.format(log_source))):
             shutil.copy2('{!s}'.format(log_source), '{!s}/{!s}'.format(
                 root_mount_point, log_destination))