xonsh 0.8.1

on Python PyPI

Added:

• SubprocSpec has a new pipeline_index integer attribute that indicates
  the commands position in a pipeline. For example, in

  .. code-block:: sh

  p = ![ls -l | grep x]

  The ls command would have a pipeline index of 0
  (p.specs[0].pipeline_index == 0) and grep would have a pipeline index
  of 1 (p.specs[1].pipeline_index == 1). This may be usefule in callable
  alaises which recieve the spec as an argument.

Changed:

• Removed fish from list of supported foreign shells in the wizard.
• Circle CI config updated to use a pinned version of black (18.9b0)
• Pytest plugin now uses xonsh.main.setup() to setup test environment.
• Linux platform discovery will no longer use platform.linux_distribution()
  on Python >=3.6.6. due to pending deprecation warning.
• Updated Linux Guide as Xonsh is now available in Arch Linux official repositories.

Fixed:

• Builtin dynamic proxies and deprecation warning proxies were not deleting
  attributes and items properly.
• Fixed stdout/sdterr writing infinite recurssion error that would occur in
  long pipelines of callable aliases.
• Fixed a bug which under very rare conditions could cause the shell
  to die with PermissionError exception while sending SIGSTOP signal
  to a child process.
• Fixed further raw string deprecation warnings thoughout the code base.