xontrib: do not autoload xontribs in `xonsh --no-rc` mode (#5586)

* no rc no autoload

* docs

---------

Co-authored-by: a <1@1.1>

docs/xonshrc.rst

@@ -25,6 +25,7 @@ In addition:
 * Use ``xonsh --rc snail.xsh`` to run only a certain control file.
 * Use ``xonsh -i script.xsh`` to run xonsh in interactive mode with loading all possible control files.
 * Use ``xonsh --rc rc1.xsh rc2.xsh -- script.xsh`` to run scripts with multiple control files.
+* You can create autoloadable `xontrib <tutorial_xontrib.html#loading-xontribs>`_ as alternative to run control file and reuse it as python package.
 
 The options set per user override settings in the system-wide control file.
 

news/norc_noautoload.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* xontrib: Do not autoload xontribs in ``xonsh --no-rc`` mode.
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>

xonsh/environ.py

@@ -1347,8 +1347,9 @@ class InterpreterSetting(Xettings):
 class XontribSetting(Xettings):
     """Xontrib Settings"""
 
-    XONTRIBS_AUTOLOAD_DISABLED = Var(
+    XONTRIBS_AUTOLOAD_DISABLED = Var.with_default(
         default=False,
+        type_str="bool",
         doc="""\
     Controls auto-loading behaviour of xontrib packages at the startup.
     * Set this to ``True`` to disable autoloading completely.

xonsh/main.py

@@ -361,8 +361,10 @@ def start_services(shell_kwargs, args, pre_env=None):
         scriptcache=shell_kwargs.get("scriptcache", True),
         cacheall=shell_kwargs.get("cacheall", False),
     )
-    XSH.load(ctx=ctx, execer=execer, inherit_env=shell_kwargs.get("inherit_env", True))
     events.on_timingprobe.fire(name="post_execer_init")
+    events.on_timingprobe.fire(name="pre_xonsh_session_load")
+    XSH.load(ctx=ctx, execer=execer, inherit_env=shell_kwargs.get("inherit_env", True))
+    events.on_timingprobe.fire(name="post_xonsh_session_load")
 
     install_import_hooks(execer)
 
@@ -370,7 +372,8 @@ def start_services(shell_kwargs, args, pre_env=None):
     for k, v in pre_env.items():
         env[k] = v
 
-    _autoload_xontribs(env)
+    if not shell_kwargs.get("norc"):
+        _autoload_xontribs(env)
     _load_rc_files(shell_kwargs, args, env, execer, ctx)
     # create shell
     XSH.shell = Shell(execer=execer, **shell_kwargs)