diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 79be79fa6..da73acda2 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -48,8 +48,7 @@ fix the bug itself.
 Fix bugs
 --------
 
-Look through the GitHub issues for bugs.  Here is a filter you can use:
-https://github.com/pytest-dev/pytest/labels/type%3A%20bug
+Look through the `GitHub issues for bugs <https://github.com/pytest-dev/pytest/labels/type:%20bug>`_.
 
 :ref:`Talk <contact>` to developers to find out how you can fix specific bugs.
 
@@ -60,8 +59,7 @@ Don't forget to check the issue trackers of your favourite plugins, too!
 Implement features
 ------------------
 
-Look through the GitHub issues for enhancements.  Here is a filter you can use:
-https://github.com/pytest-dev/pytest/labels/enhancement
+Look through the `GitHub issues for enhancements <https://github.com/pytest-dev/pytest/labels/type:%20enhancement>`_.
 
 :ref:`Talk <contact>` to developers to find out how you can implement specific
 features.
diff --git a/_pytest/helpconfig.py b/_pytest/helpconfig.py
index 5a81a5bd3..42636bdb0 100644
--- a/_pytest/helpconfig.py
+++ b/_pytest/helpconfig.py
@@ -138,7 +138,8 @@ def showhelp(config):
     tw.line("to see available markers type: pytest --markers")
     tw.line("to see available fixtures type: pytest --fixtures")
     tw.line("(shown according to specified file_or_dir or current dir "
-            "if not specified)")
+            "if not specified; fixtures with leading '_' are only shown "
+            "with the '-v' option")
 
     for warningreport in reporter.stats.get('warnings', []):
         tw.line("warning : " + warningreport.message, red=True)
diff --git a/_pytest/python.py b/_pytest/python.py
index f9f17afd7..7444819d8 100644
--- a/_pytest/python.py
+++ b/_pytest/python.py
@@ -75,7 +75,8 @@ def pytest_addoption(parser):
     group = parser.getgroup("general")
     group.addoption('--fixtures', '--funcargs',
                     action="store_true", dest="showfixtures", default=False,
-                    help="show available fixtures, sorted by plugin appearance")
+                    help="show available fixtures, sorted by plugin appearance "
+                    "(fixtures with leading '_' are only shown with '-v')")
     group.addoption(
         '--fixtures-per-test',
         action="store_true",
diff --git a/_pytest/runner.py b/_pytest/runner.py
index 6792387db..f62d34df2 100644
--- a/_pytest/runner.py
+++ b/_pytest/runner.py
@@ -105,6 +105,7 @@ def pytest_runtest_setup(item):
 
 def pytest_runtest_call(item):
     _update_current_test_var(item, 'call')
+    sys.last_type, sys.last_value, sys.last_traceback = (None, None, None)
     try:
         item.runtest()
     except Exception:
@@ -114,7 +115,7 @@ def pytest_runtest_call(item):
         sys.last_type = type
         sys.last_value = value
         sys.last_traceback = tb
-        del tb  # Get rid of it in this namespace
+        del type, value, tb  # Get rid of these in this frame
         raise
 
 
diff --git a/changelog/2798.bugfix.rst b/changelog/2798.bugfix.rst
new file mode 100644
index 000000000..dc24a724c
--- /dev/null
+++ b/changelog/2798.bugfix.rst
@@ -0,0 +1,3 @@
+Reset ``sys.last_type``, ``sys.last_value`` and ``sys.last_traceback`` before each test executes. Those attributes
+are added by pytest during the test run to aid debugging, but were never reset so they would create a leaking
+reference to the last failing test's frame which in turn could never be reclaimed by the garbage collector.
diff --git a/changelog/3398.trivial.rst b/changelog/3398.trivial.rst
new file mode 100644
index 000000000..a4e9ed12c
--- /dev/null
+++ b/changelog/3398.trivial.rst
@@ -0,0 +1 @@
+Mention in documentation and CLI help that fixtures with leading ``_`` are printed by ``pytest --fixtures`` only if the ``-v`` option is added.
diff --git a/doc/en/builtin.rst b/doc/en/builtin.rst
index 7edb1c453..554cf59b2 100644
--- a/doc/en/builtin.rst
+++ b/doc/en/builtin.rst
@@ -12,7 +12,7 @@ For information on plugin hooks and objects, see :ref:`plugins`.
 
 For information on the ``pytest.mark`` mechanism, see :ref:`mark`.
 
-For information about fixtures, see :ref:`fixtures`. To see a complete list of available fixtures, type::
+For information about fixtures, see :ref:`fixtures`. To see a complete list of available fixtures (add ``-v`` to also see fixtures with leading ``_``), type ::
 
     $ pytest -q --fixtures
     cache
diff --git a/doc/en/fixture.rst b/doc/en/fixture.rst
index 6f3debd80..fbb922d79 100644
--- a/doc/en/fixture.rst
+++ b/doc/en/fixture.rst
@@ -111,11 +111,11 @@ with a list of available function arguments.
 
 .. note::
 
-    You can always issue::
+    You can always issue ::
 
         pytest --fixtures test_simplefactory.py
 
-    to see available fixtures.
+    to see available fixtures (fixtures with leading ``_`` are only shown if you add the ``-v`` option).
 
 Fixtures: a prime example of dependency injection
 ---------------------------------------------------
@@ -141,7 +141,7 @@ automatically gets discovered by pytest. The discovery of
 fixture functions starts at test classes, then test modules, then
 ``conftest.py`` files and finally builtin and third party plugins.
 
-You can also use the ``conftest.py`` file to implement 
+You can also use the ``conftest.py`` file to implement
 :ref:`local per-directory plugins <conftest.py plugins>`.
 
 Sharing test data
diff --git a/doc/en/getting-started.rst b/doc/en/getting-started.rst
index 0965c2a61..7b9bfba57 100644
--- a/doc/en/getting-started.rst
+++ b/doc/en/getting-started.rst
@@ -166,6 +166,8 @@ Find out what kind of builtin :ref:`pytest fixtures <fixtures>` exist with the c
 
     pytest --fixtures   # shows builtin and custom fixtures
 
+Note that this command omits fixtures with leading ``_`` unless the ``-v`` option is added.
+
 Continue reading
 -------------------------------------
 
diff --git a/doc/en/test/plugin/terminal.rst b/doc/en/test/plugin/terminal.rst
index e07d4f721..bcfe53f38 100644
--- a/doc/en/test/plugin/terminal.rst
+++ b/doc/en/test/plugin/terminal.rst
@@ -23,7 +23,7 @@ command line options
 ``--full-trace``
     don't cut any tracebacks (default is to cut).
 ``--fixtures``
-    show available function arguments, sorted by plugin
+    show available fixtures, sorted by plugin appearance (fixtures with leading ``_`` are only shown with '-v')
 
 Start improving this plugin in 30 seconds
 =========================================
diff --git a/setup.py b/setup.py
index 984994a7f..8be0438ff 100644
--- a/setup.py
+++ b/setup.py
@@ -87,6 +87,10 @@ def main():
             'write_to': '_pytest/_version.py',
         },
         url='http://pytest.org',
+        project_urls={
+            'Source': 'https://github.com/pytest-dev/pytest',
+            'Tracker': 'https://github.com/pytest-dev/pytest/issues',
+        },
         license='MIT license',
         platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],
         author=(
diff --git a/testing/acceptance_test.py b/testing/acceptance_test.py
index 89a44911f..8ceb3bae1 100644
--- a/testing/acceptance_test.py
+++ b/testing/acceptance_test.py
@@ -988,3 +988,33 @@ def test_fixture_order_respects_scope(testdir):
     ''')
     result = testdir.runpytest()
     assert result.ret == 0
+
+
+def test_frame_leak_on_failing_test(testdir):
+    """pytest would leak garbage referencing the frames of tests that failed that could never be reclaimed (#2798)
+
+    Unfortunately it was not possible to remove the actual circles because most of them
+    are made of traceback objects which cannot be weakly referenced. Those objects at least
+    can be eventually claimed by the garbage collector.
+    """
+    testdir.makepyfile('''
+        import gc
+        import weakref
+
+        class Obj:
+            pass
+
+        ref = None
+
+        def test1():
+            obj = Obj()
+            global ref
+            ref = weakref.ref(obj)
+            assert 0
+
+        def test2():
+            gc.collect()
+            assert ref() is None
+    ''')
+    result = testdir.runpytest_subprocess()
+    result.stdout.fnmatch_lines(['*1 failed, 1 passed in*'])
diff --git a/testing/test_runner.py b/testing/test_runner.py
index a3bd8ecb4..7c179b1f2 100644
--- a/testing/test_runner.py
+++ b/testing/test_runner.py
@@ -719,18 +719,20 @@ def test_makereport_getsource_dynamic_code(testdir, monkeypatch):
     result.stdout.fnmatch_lines(["*test_fix*", "*fixture*'missing'*not found*"])
 
 
-def test_store_except_info_on_eror():
+def test_store_except_info_on_error():
     """ Test that upon test failure, the exception info is stored on
     sys.last_traceback and friends.
     """
-    # Simulate item that raises a specific exception
-    class ItemThatRaises(object):
+    # Simulate item that might raise a specific exception, depending on `raise_error` class var
+    class ItemMightRaise(object):
         nodeid = 'item_that_raises'
+        raise_error = True
 
         def runtest(self):
-            raise IndexError('TEST')
+            if self.raise_error:
+                raise IndexError('TEST')
     try:
-        runner.pytest_runtest_call(ItemThatRaises())
+        runner.pytest_runtest_call(ItemMightRaise())
     except IndexError:
         pass
     # Check that exception info is stored on sys
@@ -738,6 +740,13 @@ def test_store_except_info_on_eror():
     assert sys.last_value.args[0] == 'TEST'
     assert sys.last_traceback
 
+    # The next run should clear the exception info stored by the previous run
+    ItemMightRaise.raise_error = False
+    runner.pytest_runtest_call(ItemMightRaise())
+    assert sys.last_type is None
+    assert sys.last_value is None
+    assert sys.last_traceback is None
+
 
 def test_current_test_env_var(testdir, monkeypatch):
     pytest_current_test_vars = []
diff --git a/tox.ini b/tox.ini
index 75f28ca92..f4f5c3bf2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,7 +13,7 @@ envlist =
     {py27,py36}-{pexpect,xdist,trial,numpy,pluggymaster}
     py27-nobyte
     doctesting
-    py35-freeze
+    py36-freeze
     docs
 
 [testenv]
@@ -56,12 +56,11 @@ deps =
     hypothesis>=3.5.2
 changedir=testing
 commands =
-    pytest -n1 -ra {posargs:.}
+    pytest -n8 -ra {posargs:.}
 
 [testenv:py36-xdist]
 deps = {[testenv:py27-xdist]deps}
-commands =
-    pytest -n3 -ra {posargs:testing}
+commands = {[testenv:py27-xdist]commands}
 
 [testenv:py27-pexpect]
 changedir = testing
@@ -71,11 +70,10 @@ commands =
     pytest -ra test_pdb.py test_terminal.py test_unittest.py
 
 [testenv:py36-pexpect]
-changedir = testing
-platform = linux|darwin
+changedir = {[testenv:py27-pexpect]changedir}
+platform = {[testenv:py27-pexpect]platform}
 deps = {[testenv:py27-pexpect]deps}
-commands =
-    pytest -ra test_pdb.py test_terminal.py test_unittest.py
+commands = {[testenv:py27-pexpect]commands}
 
 [testenv:py27-nobyte]
 deps =
@@ -95,18 +93,16 @@ commands =
 
 [testenv:py36-trial]
 deps = {[testenv:py27-trial]deps}
-commands =
-    pytest -ra {posargs:testing/test_unittest.py}
+commands = {[testenv:py27-trial]commands}
 
 [testenv:py27-numpy]
-deps=numpy
+deps = numpy
 commands=
   pytest -ra {posargs:testing/python/approx.py}
 
 [testenv:py36-numpy]
-deps=numpy
-commands=
-  pytest -ra {posargs:testing/python/approx.py}
+deps = {[testenv:py27-numpy]deps}
+commands = {[testenv:py27-numpy]commands}
 
 [testenv:py27-pluggymaster]
 setenv=
@@ -115,12 +111,9 @@ deps =
     {[testenv]deps}
     git+https://github.com/pytest-dev/pluggy.git@master
 
-[testenv:py35-pluggymaster]
-setenv=
-    _PYTEST_SETUP_SKIP_PLUGGY_DEP=1
-deps =
-    {[testenv:py27-pluggymaster]deps}
-    git+https://github.com/pytest-dev/pluggy.git@master
+[testenv:py36-pluggymaster]
+setenv = {[testenv:py27-pluggymaster]setenv}
+deps = {[testenv:py27-pluggymaster]deps}
 
 [testenv:docs]
 skipsdist = True
@@ -176,7 +169,7 @@ changedir = testing
 commands =
     {envpython} {envbindir}/py.test-jython -ra {posargs}
 
-[testenv:py35-freeze]
+[testenv:py36-freeze]
 changedir = testing/freeze
 deps = pyinstaller
 commands =
@@ -199,7 +192,6 @@ commands =
 [pytest]
 minversion = 2.0
 plugins = pytester
-#--pyargs --doctest-modules --ignore=.tox
 addopts = -ra -p pytester --ignore=testing/cx_freeze
 rsyncdirs = tox.ini pytest.py _pytest testing
 python_files = test_*.py *_test.py testing/*/*.py