many small tweaks. base, eval, core work now i think

nanochat/common.py

@@ -93,9 +93,10 @@ def autodetect_device_type():
     # prefer to use CUDA if available, otherwise use MPS, otherwise fallback on CPU
     if torch.cuda.is_available():
         device_type = "cuda"
-    if torch.backends.mps.is_available():
+    elif torch.backends.mps.is_available():
         device_type = "mps"
-    device_type = "cpu"
+    else:
+        device_type = "cpu"
     print0(f"Autodetected device type: {device_type}")
     return device_type
 

nanochat/report.py

@@ -283,6 +283,10 @@ class Report:
                     # capture bloat data for summary later (the stuff after Bloat header and until \n\n)
                     bloat_data = re.search(r"### Bloat\n(.*?)\n\n", header_content, re.DOTALL)
                     bloat_data = bloat_data.group(1) if bloat_data else ""
+            else:
+                start_time = None # will cause us to not write the total wall clock time
+                bloat_data = "[bloat data missing]"
+                print(f"Warning: {header_file} does not exist. Did you forget to run `nanochat reset`?")
             # process all the individual sections
             for file_name in EXPECTED_FILES:
                 section_file = os.path.join(report_dir, file_name)