I can't reproduce this yet, or compare it to distutils. I 

======================================================================
ERROR: test_build_ext (packaging.tests.test_command_build_ext.BuildExtTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/unixccompiler.py", line 255, in link
    self.spawn(linker + ld_args)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/ccompiler.py", line 847, in spawn
    spawn(cmd, dry_run=self.dry_run)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/util.py", line 783, in spawn
    raise PackagingExecError(msg % (cmd, exit_status))
packaging.errors.PackagingExecError: command '['gcc', '-pthread', '-shared', '/tmp/tmpwe7ci9/tmp3v8m7p/tmp/tmpwe7ci9/tmp3v8m7p/xxmodule.o', '-L.', '-lpython3.3', '-o', '/tmp/tmpwe7ci9/tmp3v8m7p/xx.cpython-33dm.so']' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/tests/test_command_build_ext.py", line 59, in test_build_ext
    cmd.run()
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/command/build_ext.py", line 345, in run
    self.build_extensions()
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/command/build_ext.py", line 368, in build_extensions
    self.build_extension(ext)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/command/build_ext.py", line 454, in build_extension
    target_lang=language)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/ccompiler.py", line 675, in link_shared_object
    extra_preargs, extra_postargs, build_temp, target_lang)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/unixccompiler.py", line 257, in link
    raise LinkError(msg)
packaging.errors.LinkError: command '['gcc', '-pthread', '-shared', '/tmp/tmpwe7ci9/tmp3v8m7p/tmp/tmpwe7ci9/tmp3v8m7p/xxmodule.o', '-L.', '-lpython3.3', '-o', '/tmp/tmpwe7ci9/tmp3v8m7p/xx.cpython-33dm.so']' failed with exit status 1

======================================================================
ERROR: test_get_outputs (packaging.tests.test_command_build_ext.BuildExtTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/unixccompiler.py", line 255, in link
    self.spawn(linker + ld_args)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/ccompiler.py", line 847, in spawn
    spawn(cmd, dry_run=self.dry_run)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/util.py", line 783, in spawn
    raise PackagingExecError(msg % (cmd, exit_status))
packaging.errors.PackagingExecError: command '['gcc', '-pthread', '-shared', '/tmp/tmpdfxahd/tmp0m_s9d/tempt/tmp/tmpdfxahd/tmp_cb75f/foo.o', '-L.', '-lpython3.3', '-o', '/tmp/tmpdfxahd/tmpcoi8oo/foo.cpython-33dm.so']' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/tests/test_command_build_ext.py", line 263, in test_get_outputs
    cmd.run()
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/command/build_ext.py", line 345, in run
    self.build_extensions()
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/command/build_ext.py", line 368, in build_extensions
    self.build_extension(ext)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/command/build_ext.py", line 454, in build_extension
    target_lang=language)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/ccompiler.py", line 675, in link_shared_object
    extra_preargs, extra_postargs, build_temp, target_lang)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/packaging/compiler/unixccompiler.py", line 257, in link
    raise LinkError(msg)
packaging.errors.LinkError: command '['gcc', '-pthread', '-shared', '/tmp/tmpdfxahd/tmp0m_s9d/tempt/tmp/tmpdfxahd/tmp_cb75f/foo.o', '-L.', '-lpython3.3', '-o', '/tmp/tmpdfxahd/tmpcoi8oo/foo.cpython-33dm.so']' failed with exit status 1

I just ran a manual build/test on the buildbot, and these underlying failures appear to be due to the "-l python3.3" option, which can't be found.  I also don't see that library in the build tree.  Instead, the library is built as python3.3dm (the buildbot process uses --with-pydebug and --with-pymalloc is now default in 3.2+).

Haven't dug much deeper than that, so not sure how the packaging tests are figuring out the shared library to link with.  I did verify that the sysconfig module variables that are related do all have the dm suffix information so it should be available to the tests.

-- David

Thanks for the test David