packaging: replace a documentation reference to `python3` on Windows

Sadly, there's not `python3.exe` on Windows.

Differential Revision: https://phab.mercurial-scm.org/D9937

contrib/packaging/inno/readme.rst

@@ -1,61 +1,61 b''
 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 ``packaging.py`` script)
 
 Building
 ========
 
 The ``packaging.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 ``packaging.py`` to produce an Inno installer. You will
 need to supply the path to the Python interpreter to use.::
 
-   $ python3.exe contrib\packaging\packaging.py \
+   $ py -3 contrib\packaging\packaging.py \
        inno --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
 ``packaging.py inno --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 ``packaging.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.

contrib/packaging/wix/readme.rst

@@ -1,71 +1,71 b''
 WiX Installer
 =============
 
 The files in this directory are used to produce an MSI installer using
 the WiX Toolset (http://wixtoolset.org/).
 
 The MSI installers require elevated (admin) privileges due to the
 installation of MSVC CRT libraries into the Windows system store. See
 the Inno Setup installers in the ``inno`` sibling directory for installers
 that do not have this requirement.
 
 Requirements
 ============
 
 Building the WiX installers requires a Windows machine. The following
 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)
 * Python 3.5+ (to run the ``packaging.py`` script)
 
 Building
 ========
 
 The ``packaging.py`` script automates the process of producing an MSI
 installer. It manages fetching and configuring 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 ``packaging.py`` to produce an MSI installer. You will need
 to supply the path to the Python interpreter to use.::
 
-   $ python3 contrib\packaging\packaging.py \
+   $ py -3 contrib\packaging\packaging.py \
       wix --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. An error is raised otherwise.
 
 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 ``packaging.py wix --help`` to
 see a list of program flags.
 
 Relationship to TortoiseHG
 ==========================
 
 TortoiseHG uses the WiX files in this directory.
 
 The code for building TortoiseHG installers lives at
 https://bitbucket.org/tortoisehg/thg-winbuild and is maintained by
 Steve Borho ([e-mail]).
 
 When changing behavior of the WiX installer, be sure to notify
 the TortoiseHG Project of the changes so they have ample time
 provide feedback and react to those changes.