Xonsh

====================
**Added:**

* ``trace`` alias added that enables users to turn on and off the printing
of source code lines prior to their execution. This is useful for debugging scripts.
* New ability to force callable alias functions to be run in the foreground, i.e.
the main thread from which the function was called. This is useful for debuggers
and profilers which may require such access. Use the ``xonsh.proc.foreground``
decorator on an alias function to flag it. ``ForegroundProcProxy`` and
``SimpleForegroundProcProxy`` classes have been added to support this feature.
Normally, forcing a foreground alias is not needed.
* Added boolean ``$RAISE_SUBPROC_ERROR`` environment variable. If true
and a subprocess command exits with a non-zero return code, a
CalledProcessError will be raised. This is useful in scripts that should
fail at the first error.
* If the ``setproctitle`` package is installed, the process title will be
set to ``'xonsh'`` rather than the path to the Python interpreter.
* zsh foreign shell interface now supported natively in xonsh, like with Bash.
New ``source-zsh`` alias allows easy access to zsh scripts and functions.
* Vox virtual environment manager added.

**Changed:**

* The ``foreign_shell_data()`` keyword arguments ``envcmd`` and ``aliascmd``
now default to ``None``.
* Updated alias docs to pull in usage from the commands automatically.

**Fixed:**

* Hundreds of bugs related to line and column numbers have been addressed.
* Fixed path completion not working for absolute paths or for expanded paths on Windows.
* Fixed issue with hg dirty branches and $PATH.
* Fixed issues related to foreign shell data in files with whitespace in the names.
* Worked around bug in ConEmu/cmder which prevented ``get_git_branch()``
from working in these terminal emulators on Windows.

===========
**Added:**

* New configuration utility 'xonfig' which reports current system
setup information and creates config files through an interactive
wizard.
* Toolkit for creating wizards now available
* timeit and which aliases will now complete their arguments.
* $COMPLETIONS_MENU_ROWS environment variable controls the size of the
tab-completion menu in prompt-toolkit.
* Prompt-toolkit shell now supports true multiline input with the ability
to scroll up and down in the prompt.

**Changed:**

* The xonfig wizard will run on interactive startup if no configuration
file is found.
* BaseShell now has a singleline() method for prompting a single input.
* Environment variable docs are now auto-generated.
* Prompt-toolkit shell will now dynamically allocate space for the
tab-completion menu.
* Looking up nonexistent environment variables now generates an error
in Python mode, but produces a sane default value in subprocess mode.
* Environments are now considered to contain all manually-adjusted keys,
and also all keys with an associated default value.

**Removed:**

* Removed ``xonsh.ptk.shortcuts.Prompter.create_prompt_layout()`` and
``xonsh.ptk.shortcuts.Prompter.create_prompt_application()`` methods
to reduce portion of xonsh that forks prompt-toolkit. This may require
users to upgrade to prompt-toolkit v0.57+.

**Fixed:**

* First prompt in the prompt-toolkit shell now allows for up and down
arrows to search through history.
* Made obtaining the prompt-toolkit buffer thread-safe.
* Now always set non-detypable environment variables when sourcing
foreign shells.
* Fixed issue with job management if a TTY existed but was not controlled
by the process, posix only.
* Jupyter kernel no longer times out when using foreign shells on startup.
* Capturing redirections, e.g. ``$(echo hello > f.txt)``, no longer fails
with a decoding error.
* Evaluation in a Jupyter cell will return pformatted object.
* Jupyter with redirect uncaptured subprocs to notebook.
* Tab completion in Jupyter fixed.

===============
You are reading the docs...but you still feel hungry.

=============
**Added:**

* Rich history recording and replaying

=============
The before times, like 65,000,000 BCE.