tests/test-demandimport.py

demandimport: blacklist distutils.msvc9compiler (issue4475)

This module depends on _winreg, which is windows-only. Recent versions
of setuptools load distutils.msvc9compiler and expect it to
ImportError immediately when on non-Windows platforms, so we need to
let them do that. This breaks in an especially mystifying way, because
setuptools uses vars() on the imported module. We then throw an
exception, which vars doesn't pick up on well. For example:

In [3]: class wat(object):
   ...:     @property
   ...:     def __dict__(self):
   ...:         assert False
   ...:

In [4]: vars(wat())
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-4-2781ada5ffe6> in <module>()
----> 1 vars(wat())

TypeError: vars() argument must have __dict__ attribute

Which is similar to the problem we run into.

from mercurial import demandimport
demandimport.enable()

import os
if os.name != 'nt':
    try:
        import distutils.msvc9compiler
        print ('distutils.msvc9compiler needs to be an immediate '
               'importerror on non-windows platforms')
        distutils.msvc9compiler
    except ImportError:
        pass

import re

rsub = re.sub
def f(obj):
    l = repr(obj)
    l = rsub("0x[0-9a-fA-F]+", "0x?", l)
    l = rsub("from '.*'", "from '?'", l)
    l = rsub("'<[a-z]*>'", "'<whatever>'", l)
    return l

import os

print "os =", f(os)
print "os.system =", f(os.system)
print "os =", f(os)

from mercurial import util

print "util =", f(util)
print "util.system =", f(util.system)
print "util =", f(util)
print "util.system =", f(util.system)

import re as fred
print "fred =", f(fred)

import sys as re
print "re =", f(re)

print "fred =", f(fred)
print "fred.sub =", f(fred.sub)
print "fred =", f(fred)

print "re =", f(re)
print "re.stderr =", f(re.stderr)
print "re =", f(re)

demandimport.disable()
os.environ['HGDEMANDIMPORT'] = 'disable'
demandimport.enable()
from mercurial import node
print "node =", f(node)