contrib/packaging/inno/readme.rst

setup: configure py2exe config via environment variables

The Inno Setup and WiX installers ship a different set of packages
with py2exe builds. And there are multiple WiX installer variants
(e.g. TortoiseHG).

Since there are multiple variants of py2exe configs and they
can be defined by entities not in our repository, let's
provide a mechanism for setup.py to supplement behavior via
environment variables. This is slighly less hacky than a setup.cfg
file IMO since the caller doesn't need to worry about mutating
global state of the source directory.

Differential Revision: https://phab.mercurial-scm.org/D6092

Requirements
============

Building the Inno installer requires a Windows machine.

The following system dependencies must be installed:

* Python 2.7 (download from https://www.python.org/downloads/)
* Microsoft Visual C++ Compiler for Python 2.7
  (https://www.microsoft.com/en-us/download/details.aspx?id=44266)
* Inno Setup (http://jrsoftware.org/isdl.php) version 5.4 or newer.
  Be sure to install the optional Inno Setup Preprocessor feature,
  which is required.
* Python 3.5+ (to run the ``build.py`` script)

Building
========

The ``build.py`` script automates the process of producing an
Inno installer. It manages fetching and configuring the
non-system dependencies (such as py2exe, gettext, and various
Python packages).

The script requires an activated ``Visual C++ 2008`` command prompt.
A shortcut to such a prompt was installed with ``Microsoft Visual C++
Compiler for Python 2.7``. From your Start Menu, look for
``Microsoft Visual C++ Compiler Package for Python 2.7`` then launch
either ``Visual C++ 2008 32-bit Command Prompt`` or
``Visual C++ 2008 64-bit Command Prompt``.

From the prompt, change to the Mercurial source directory. e.g.
``cd c:\src\hg``.

Next, invoke ``build.py`` to produce an Inno installer. You will
need to supply the path to the Python interpreter to use.:

   $ python3.exe contrib\packaging\inno\build.py \
       --python c:\python27\python.exe

.. note::

   The script validates that the Visual C++ environment is
   active and that the architecture of the specified Python
   interpreter matches the Visual C++ environment and errors
   if not.

If everything runs as intended, dependencies will be fetched and
configured into the ``build`` sub-directory, Mercurial will be built,
and an installer placed in the ``dist`` sub-directory. The final
line of output should print the name of the generated installer.

Additional options may be configured. Run ``build.py --help`` to
see a list of program flags.

MinGW
=====

It is theoretically possible to generate an installer that uses
MinGW. This isn't well tested and ``build.py`` and may properly
support it. See old versions of this file in version control for
potentially useful hints as to how to achieve this.