It seems like this change:

     def test_forced_io_encoding(self):
         # Checks forced configuration of embedded interpreter IO streams
-        out, err = self.run_embedded_interpreter("forced_io_encoding")
-        if support.verbose:
+        env = {"PYTHONIOENCODING": "utf-8:surrogateescape"}
+        out, err = self.run_embedded_interpreter("forced_io_encoding", env=env)
(...)

Caused a failure on the "shared" buildbot (./configure --enable-shared):

http://buildbot.python.org/all/builders/x86%20Ubuntu%20Shared%203.x/builds/877/steps/test/logs/stdio

======================================================================
FAIL: test_forced_io_encoding (test.test_capi.EmbeddingTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/test_capi.py", line 484, in test_forced_io_encoding
    out, err = self.run_embedded_interpreter("forced_io_encoding", env=env)
  File "/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Lib/test/test_capi.py", line 392, in run_embedded_interpreter
    (p.returncode, err))
AssertionError: 127 != 0 : bad returncode 127, stderr is '/srv/buildbot/buildarea/3.x.bolen-ubuntu/build/Programs/_testembed: error while loading shared libraries: libpython3.7dm.so.1.0: cannot open shared object file: No such file or directory\n'