don't use utils.process in nbconvert

use shutil.which and Popen

jupyter_nbconvert/filters/markdown.py

@@ -23,7 +23,6 b' except ImportError as e:'
 
 from jupyter_nbconvert.utils.pandoc import pandoc
 from jupyter_nbconvert.utils.exceptions import ConversionException
-from IPython.utils.process import get_output_error_code
 from IPython.utils.py3compat import cast_bytes
 from IPython.utils.version import check_version
 
@@ -130,11 +129,14 b' def _verify_node(cmd):'
     cmd : string
         Node command to verify (i.e 'node')."""
     try:
-        out, err, return_code = get_output_error_code([cmd, '--version'])
+        p = subprocess.Popen([cmd, '--version'],
+            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        out, _ = p.communicate()
+        out = out.decode('utf8', 'replace')
     except OSError:
         # Command not found
         return False
-    if return_code:
+    if p.returncode:
         # Command error
         return False
     return check_version(out.lstrip('v'), '0.9.12')

jupyter_nbconvert/tests/base.py

@@ -10,13 +10,14 b' import shlex'
 import shutil
 import sys
 import unittest
+from subprocess import Popen, PIPE
 
 import nose.tools as nt
 
 from IPython.nbformat import v4, write
 from IPython.utils.tempdir import TemporaryWorkingDirectory
-from IPython.utils.process import get_output_error_code
-from IPython.utils.py3compat import string_types
+
+from IPython.utils.py3compat import string_types, bytes_to_str
 
 class TestsBase(unittest.TestCase):
     """Base tests class.  Contains useful fuzzy comparison and nbconvert
@@ -141,11 +142,13 b' class TestsBase(unittest.TestCase):'
         if isinstance(parameters, string_types):
             parameters = shlex.split(parameters)
         cmd = [sys.executable, '-m', 'jupyter_nbconvert'] + parameters
-        stdout, stderr, retcode = get_output_error_code(cmd)
-        if not (retcode == 0 or ignore_return_code):
-            raise OSError(stderr)
-        return stdout, stderr
-    
+        p = Popen(cmd, stdout=PIPE, stderr=PIPE)
+        stdout, stderr = p.communicate()
+        if not (p.returncode == 0 or ignore_return_code):
+            raise OSError(bytes_to_str(stderr))
+        return stdout.decode('utf8', 'replace'), stderr.decode('utf8', 'replace')
+
+
 def assert_big_text_equal(a, b, chunk_size=80):
     """assert that large strings are equal
 

jupyter_nbconvert/utils/pandoc.py

@@ -11,7 +11,7 b' from io import TextIOWrapper, BytesIO'
 
 from IPython.utils.py3compat import cast_bytes
 from IPython.utils.version import check_version
-from IPython.utils.process import is_cmd_found, FindCmdError
+from IPython.utils.py3compat import which
 
 from .exceptions import ConversionException
 
@@ -71,7 +71,7 b' def get_pandoc_version():'
     global __version
 
     if __version is None:
-        if not is_cmd_found('pandoc'):
+        if not which('pandoc'):
             raise PandocMissing()
 
         out = subprocess.check_output(['pandoc', '-v'],