[PATCH] win32 installer for bzr 0.9: rev.2

Tue Aug 1 00:18:42 BST 2006

John Arbash Meinel пишет:
> 
>>> I also feel like it would be better to use
>>> sys.executable, rather than joining prefix + 'python.exe'.
>> No. Your feelings is wrong. This script (bzr-win32-bdist-postinstall.py)
>> launched during installation phase when user runs bzr-0.9.win32.exe
>> installer. And for this script sys.executable equals to full path to
>> installer. Not to python interpreter. So "prefix + 'python.exe'" is right.
>>
> I think you are saying you spawn 'python
> bzr-win32-bdist-postinstall.py', or the equivalent.
> 
> sys.executable == a python executable, *not* the script that is running
> (that is sys.argv[0])
> 
> If sys.executable == 'bzr-0.9.win32.exe', how do you know that it is
> sitting in the same directory as 'python.exe'?
> 
> I think I understand that bzr-0.9.win32.exe is just the installer, not a
> python interpreter. Which would mean that you still should use
> 'sys.executable'.

I try to clarify a bit. Script bzr-win32-bdist-postinstall.py designed 
exclusively to use with python-based installer. This script designed in 
accordance with python documentation 'Distributing Python Modules' 
section '5.3 Creating Windows Installers', subsection 'The 
Postinstallation scripts'.
http://docs.python.org/dist/postinstallation-script.html#SECTION005310000000000000000

This document in particular says:
--------------------------------------------------------------------------
This script will be run at installation time on the target system after 
all the files have been copied, with argv[1] set to -install, and again 
at uninstallation time before the files are removed with argv[1] set to 
-remove.

The installation script runs embedded in the windows installer, every 
output (sys.stdout, sys.stderr) is redirected into a buffer and will be 
displayed in the GUI after the script has finished.
-------------------------------------------------------------------------

I create simple testing postinstall script to inspect values of 
different path variables. Content of this script:
-------------------------------------------------
import os
import sys

if "-install" in sys.argv[1:]:
     print 'sys.argv:', sys.argv
     print 'sys.executable:', sys.executable
     print 'sys.prefix:', sys.prefix
     print 'sys.exec_prefix:', sys.exec_prefix
     print 'os.getcwd():', os.getcwd()
-------------------------------------------------

This script launched automatically by python-based installer as last 
step of installation (after all source files is copied). Output of this 
script is sown at the last screen of installation wizard. Here 
copy-pasted text. Also see attached screenshot.
-------------------------------------------------
sys.argv: ['C:\\Python24\\Scripts\\bzr-win32-bdist-postinstall.py', 
'-install']
sys.executable: 
E:\Bazaar-NG\devel\python-installer\dist\bzr-0.9.0dev0.win32.exe
sys.prefix: C:\Python24
sys.exec_prefix: C:\Python24
os.getcwd(): E:\Bazaar-NG\devel\python-installer\dist
-------------------------------------------------

Documentation of sys module says:
-------------------------------------------------------------------------
exec_prefix
A string giving the site-specific directory prefix where the 
platform-dependent Python files are installed; by default, this is also 
'/usr/local'. This can be set at build time with the --exec-prefix 
argument to the configure script. Specifically, all configuration files 
(e.g. the pyconfig.h header file) are installed in the directory 
exec_prefix + '/lib/pythonversion/config', and shared library modules 
are installed in exec_prefix + '/lib/pythonversion/lib-dynload', where 
version is equal to version[:3].

executable
A string giving the name of the executable binary for the Python 
interpreter, on systems where this makes sense.

prefix
A string giving the site-specific directory prefix where the platform 
independent Python files are installed; by default, this is the string 
'/usr/local'. This can be set at build time with the --prefix argument 
to the configure script. The main collection of Python library modules 
is installed in the directory prefix + '/lib/pythonversion' while the 
platform independent header files (all except pyconfig.h) are stored in 
prefix + '/include/pythonversion', where version is equal to version[:3].
--------------------------------------------------------------------------

But built-in help for module sys very brief here:
--------------------------------------------------------------------------
executable -- pathname of this Python interpreter
prefix -- prefix used to find the Python library
exec_prefix -- prefix used to find the machine-specific Python library
--------------------------------------------------------------------------

As you can see postinstall script running by installer itself (I suppose 
that installer use Python C/API to load and execute this script, with 
function like Py_Main or something similar). Both sys.prefix and 
sys.exec_prefix is very similar to each other, and I don't see 
difference between them on Windows. Although, C:\Python24\Scripts seems 
to be platform-dependent location (AFAIK, on Linux executable scripts 
installed directly to /usr/bin or /usr/sbin). Probably I need to use 
sys.exec_prefix as directory where python.exe is located.

If we want to be *really* paranoid, we can do additional check that 
python.exe actually exists at os.path.join(sys.exec_prefix, 
'python.exe') or try to build path to python.exe from sys.argv[0] 
because python.exe on windows usually in directory one level up relative 
to Scripts, or we can try to search python installation directory by 
looking at windows registry (latter can't works if user don't install 
python as usual but instead build it from sources or simply copying from 
archive or another machine).

I think sys.exec_prefix is what we need. And we don't need to be paranoid.

>>> ...Why is this failing? Because the standalone doesn't have a 'doc/api'
>>> directory?
>> It's failing because in standalone bzr.exe bzrlib itself packed inside
>> library.zip archive. So it simply cannot be os-listdir-able. When I work
>> on installer in early may I ask about this. You can search trough
>> maillist archive. Someone point me that doctest could be improved to use
>> zipimport module to actually obtain list of packed *.txt files with
>> doctests. But I looks too complex for this minor issue.
>>
> Yeah, you mentioned this briefly already, I'm okay with what you are doing.

Before I forget some important details so I think it's OK to explain 
things more clear.

>> +Making installers for OS Windows
>> +================================
>> +To build a win32 installer, see the instructions at wiki page:
>> +http://bazaar-vcs.org/BzrWin32Installer
>> +
>> +
>>  :: vim: ft=rst tw=74 ai
> 
> 'see the instructions on the wiki page:'

Ah, sorry. Thanks for fix.
I think I should to looking for english training courses.

>>  # win32 installer for bzr.exe
>>  installer: exe copy_docs
>> -	@echo Make windows installer
>> -	cog.py -d -o tools\win32\bzr.iss tools\win32\bzr.iss.cog
>> -	"C:\Program Files\Inno Setup 5\iscc" /Q tools\win32\bzr.iss
>> +	@echo *** Make windows installer
>> +	cog.py -d -o tools/win32/bzr.iss tools/win32/bzr.iss.cog
>> +	iscc /Q tools/win32/bzr.iss
> 
> Shouldn't this be 'python cog.py' to be consistent with your other changes.

It's very thin here.

No, it shouldn't be 'python cog.py' because in this case we need to 
specify full path to cog.py and this path potentially could be something 
like 'C:\Python24\Scripts\cog.py' but if user install Python to 
different (not default) directory this path will be wrong. In my 
instruction about installer I say that user should add both 
'C:\Python24' and 'C:\Python24\Scripts' to $PATH environment variable, 
so running cog.py simply by name should work on both Windows and Linux.

In other cases I use form 'python path/to/script.py' to avoid difference 
between Windows and Linux (on Linux I have to use something like 
'./path/to/script.py' or simply './script.py').

> v--- It seems like it would be better to do:
> META_INFO.update({'version':get_bzr_version()})
> Earlier, rather than having to do it twice. Especially since you've
> already updated ARGS, which would set version = '<unknown>'
> Is there a code path that doesn't need version to be set?

Actually -- yes, py2exe's path don't use this version info. But at other 
side it absolutely harmless to set it up in one place for all 
installers. I'll change this.

> I think it is just about ready for merging. If you can do the last few
> bits, we'll get it merged this week.
OK.

--
Alexander
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