diff --git a/.gitignore b/.gitignore
index fa1ab38ae2..470910f13d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,6 @@ python/benchmark/*.html
 .env
 .vscode
 env
+# pixi environments
+.pixi/*
+!.pixi/config.toml
diff --git a/python/.gitignore b/python/.gitignore
index 5a5029de6d..bba8f51b92 100644
--- a/python/.gitignore
+++ b/python/.gitignore
@@ -5,3 +5,6 @@ build
 .*.swp
 .*.swo
 */.ipynb_checkpoints
+# pixi environments
+.pixi/*
+!.pixi/config.toml
diff --git a/python/tskit/util.py b/python/tskit/util.py
index 64fad3f423..317833c158 100644
--- a/python/tskit/util.py
+++ b/python/tskit/util.py
@@ -30,6 +30,7 @@
 import json
 import numbers
 import os
+import sys
 import textwrap
 from typing import Union
 
@@ -878,6 +879,10 @@ def raise_known_file_format_errors(open_file, existing_exception):
     Sniffs the file for pk-zip or hdf header bytes, then raises an exception
     if these are detected, if not raises the existing exception.
     """
+    if (sys.version_info[0] >= 3) & (sys.version_info[1] > 10):
+        # add_note has been added in python 3.11
+        # This condition can be removed once 3.10 is end-of-life
+        existing_exception.add_note(f"While trying to load {open_file.name}")
     # Check for HDF5 header bytes
     try:
         open_file.seek(0)
@@ -887,16 +892,16 @@ def raise_known_file_format_errors(open_file, existing_exception):
         raise existing_exception
     if header == b"\x89HDF":
         raise tskit.FileFormatError(
-            "The specified file appears to be in HDF5 format. This file "
+            f"The file {open_file.name} appears to be in HDF5 format. This file "
             "may have been generated by msprime < 0.6.0 (June 2018) which "
             "can no longer be read directly. Please convert to the new "
             "kastore format using the ``tskit upgrade`` command from tskit version<0.6.2"
         ) from existing_exception
     if header[:2] == b"\x50\x4b":
         raise tskit.FileFormatError(
-            "The specified file appears to be in zip format, so may be a compressed "
-            "tree sequence. Try using the tszip module to decompress this file before "
-            "loading. `pip install tszip; tsunzip <filename>` or use "
+            f"The file {open_file.name} appears to be in zip format, so may be a "
+            "compressed tree sequence. Try using the tszip module to decompress this "
+            "file before loading. `pip install tszip; tsunzip <filename>` or use "
             "`tszip.decompress` in Python code."
         ) from existing_exception
     raise existing_exception