Warn on suite_version mismatch in comparison view

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: mattip

codespeed/static/js/comparison.js

@@ -52,6 +52,22 @@ function refreshContent() {
       msg = '<p class="warning">Normalized stacked bars actually represent the weighted arithmetic sum, useful to spot which individual benchmarks take up the most time. Choosing different weightings from the "Normalization" menu will change the totals relative to one another. For the correct way to calculate total bars, the geometric mean must be used (see <a href="http://portal.acm.org/citation.cfm?id=5666.5673 " title="How not to lie with statistics: the correct way to summarize benchmark results">paper</a>)</p>';
   }
 
+  if (compdata && compdata.suite_versions) {
+    var mismatchedEnvs = enviros.filter(function(envId) {
+      var versions = new Set();
+      exes.forEach(function(exeKey) {
+        var sv = compdata.suite_versions[exeKey];
+        if (sv && sv[envId]) {
+          sv[envId].forEach(function(v) { versions.add(v); });
+        }
+      });
+      return versions.size > 1;
+    });
+    if (mismatchedEnvs.length > 0) {
+      msg += '<p class="warning">The executables being compared used different benchmark suite versions. Results may not be directly comparable.</p>';
+    }
+  }
+
   chartInstances.forEach(function(c) { c.destroy(); });
   chartInstances = [];
   $("#plotwrapper").fadeOut("fast", function() {

codespeed/views.py

@@ -222,26 +222,37 @@ def getcomparisondata(request):
 
     compdata = {}
     compdata['error'] = "Unknown error"
+    suite_versions = {}  # exe_key -> env_id -> sorted list of unique non-empty versions
     for proj in executables:
         for exe in executables[proj]:
             if requested_exes is not None and exe['key'] not in requested_exes:
                 continue
             compdata[exe['key']] = {}
+            suite_versions[exe['key']] = {}
             for env in environments:
                 compdata[exe['key']][env.id] = {}
 
                 # Load all results for this env/executable/revision in a
                 # dict for fast lookup
-                results = dict(Result.objects.filter(
+                rows = Result.objects.filter(
                     environment=env,
                     executable=exe['executable'],
                     revision=exe['revision'],
-                ).values_list('benchmark', 'value'))
+                ).values_list('benchmark', 'value', 'suite_version')
+
+                results = {}
+                env_versions = set()
+                for bench_id, value, sv in rows:
+                    results[bench_id] = value
+                    if sv:
+                        env_versions.add(sv)
 
                 for bench in benchmarks:
                     compdata[exe['key']][env.id][bench.id] = results.get(
                         bench.id, None)
+                suite_versions[exe['key']][env.id] = sorted(env_versions)
 
+    compdata['suite_versions'] = suite_versions
     compdata['error'] = "None"
 
     return HttpResponse(json.dumps(compdata))