setup: test whether the build system prefers binary dists which are new enough over source dists which are even newer

ref: #1233

misc/build_helpers/test-with-fake-dists.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+
+# We put a fake "pycryptopp-0.5.24.egg" package and a fake
+# "pycryptopp-9.9.99.tar.gz" into a directory, but the latter is
+# booby-trapped so it will raise an exception when you try to build
+# it.
+
+# Then we run "python setup.py test -s
+# buildtest.test_with_fake_dist", which imports pycryptopp
+# and passes if pycryptopp.__version__ == '0.5.24'.
+
+# (If building succeeded -- meaning that you didn't try to build the
+# booby-trapped 9.9.99 -- but pycryptopp.__version__ != '0.5.24' then
+# that means a different version of pycryptopp was already installed
+# so neither of the two fake pycryptopp packages were needed. In that
+# case this test should be treated as a "skip" -- the functionality
+# under test can't be exercised on the current system.)
+
+# The goal is to turn red if the build system tries to build the
+# source dist when it could have used the binary dist.
+
+# (Note that for this test to make sense, tahoe-lafs needs to be
+# asking for a version of pycryptopp which can be satisfied by either
+# 0.5.24 or 0.5.25. At the time of this writing it requires >= 0.5.20
+# on x86 and >= 0.5.14 on other architectures.)
+
+import StringIO, glob, os, platform, subprocess, sys, tarfile, zipfile
+import pkg_resources
+
+fake_distdir = 'tahoe-deps'
+fake_distname = "pycryptopp"
+fake_sdistversion = "9.9.99"
+fake_bdistversion = "0.5.24"
+sdist_setup = "raise Exception('Aha I caught you trying to build me. I am a fake pycryptopp 9.9.99 sdist and you should be satisfied with a bdist.')"
+
+testsuite = "buildtest.test_build_with_fake_dist"
+
+dist_dirname = os.path.join(os.getcwd(), fake_distdir)
+
+try:
+    os.makedirs(dist_dirname)
+except OSError:
+    # probably already exists
+    pass
+
+bdist_egg_name = os.path.join(dist_dirname, '%s-%s-py%s.%s-%s.egg' % (fake_distname, fake_bdistversion, platform.python_version_tuple()[0], platform.python_version_tuple()[1], pkg_resources.get_supported_platform()))
+try:
+    bdist_egg = zipfile.ZipFile(bdist_egg_name, 'w')
+    bdist_egg.writestr('pycryptopp/__init__.py', '__version__ = "%s"\n' % (fake_bdistversion,))
+    bdist_egg.close()
+
+    sdist_name = os.path.join(dist_dirname, '%s-%s.tar' % (fake_distname, fake_sdistversion))
+    sdist = tarfile.open(sdist_name, 'w:gz')
+    sdist.errorlevel =2
+    tarinfo = tarfile.TarInfo('setup.py')
+    tarinfo.errorlevel =2
+    tarinfo.size = len(sdist_setup)
+    sdist.addfile(tarinfo, StringIO.StringIO(sdist_setup))
+    sdist.close()
+
+    setuppy="setup.py"
+    os.environ['PATH']=os.path.join(os.getcwd(), 'src')+os.pathsep+os.environ['PATH']
+    eggs = [os.path.realpath(p) for p in glob.glob(os.path.join('..', '*.egg')) if not 'pycryptopp' in p]
+    os.environ['PYTHONPATH']=os.pathsep+os.pathsep.join(eggs)+os.pathsep+os.environ.get('PYTHONPATH','')
+    sys.exit(subprocess.call([sys.executable, setuppy, "-v", "test", "-s", testsuite], env=os.environ))
+finally:
+    os.remove(bdist_egg_name)
+    os.remove(sdist_name)
+    pass

src/buildtest/test_build_with_fake_dist.py

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+from twisted.trial import unittest
+
+class T(unittest.TestCase):
+    def test_version(self):
+        import pycryptopp
+        if pycryptopp.__version__ != '0.5.24':
+            raise unittest.SkipTest("We can't tell if this worked because this system has a different version of pycryptopp already installed. See comment in misc/build_helpers/test-with-fake-dists.py for details.")
+        self.succeed()