must include all changed files..

docs/tutorial.rst

@@ -1176,6 +1176,8 @@ function with the ``xonsh.proc.foreground`` decorator.
 Aliasing is a powerful way that xonsh allows you to seamlessly interact to
 with Python and subprocess.
 
+.. warning:: Foreign shell aliases that try to override xonsh aliases will be ignored
+
 Up, Down, Tab
 ==============
 The up and down keys search history matching from the start of the line,

xonsh/foreign_shells.py

@@ -582,9 +582,10 @@ def load_foreign_aliases(shells=None, config=None, issue_warning=True):
         _, shaliases = foreign_shell_data(**shell)
         for alias in set(shaliases) & set(xonsh_aliases):
             del shaliases[alias]
-            print('aliases: alias {!r} of shell {!r} '
-                  'tries to override xonsh alias, '
-                  'xonsh wins!'.format(alias, shell['shell']),
-                  file=sys.stderr)
+            if builtins.__xonsh_env__.get('XONSH_DEBUG'):
+                print('aliases: ignoring alias {!r} of shell {!r} '
+                      'which tries to override xonsh alias.'
+                      ''.format(alias, shell['shell']),
+                      file=sys.stderr)
         aliases.update(shaliases)
     return aliases