Apply suggestions from code review

Co-authored-by: Oliver Sanders <[email protected]>

CHANGES.md

@@ -8,8 +8,8 @@ ones in. -->
 
 ## __cylc-rose-1.4.2 (<span actions:bind='release-date'>Upcoming</span>)__
 
-[#345](https://github.com/cylc/cylc-rose/pull/345) - Merge new CLI
-options with earlier ones when validating against source.
+[#345](https://github.com/cylc/cylc-rose/pull/345) - Fix an issue
+where `cylc vr` could report erroneous validation failures.
 
 ## __cylc-rose-1.4.1 (<span actions:bind='release-date'>Released 2024-07-23</span>)__
 

cylc/rose/utilities.py

@@ -1013,7 +1013,6 @@ def retrieve_installed_cli_opts(srcdir, opts):
     Allows validation of merged config for pre-configure where the
     --against-source argument is used in a Cylc script.
     """
-
     # if opts.against_source is a path then we are validating a source
     # directory against installed options
     rundir = opts.against_source
@@ -1040,6 +1039,7 @@ def retrieve_installed_cli_opts(srcdir, opts):
     # Work out whether user has used "template variables", "jinja2:suite.rc"
     # or "empy:suite.rc" (There is an assumption that they aren't mixing
     # them that is not guarded against):
+    template_variables = []
     for section in SECTIONS:
         if cli_config.value.get(section, False):
             template_variables = cli_config.value.pop(section)