diff --git a/mitogen/parent.py b/mitogen/parent.py
index 024f5c14..6ca6369a 100644
--- a/mitogen/parent.py
+++ b/mitogen/parent.py
@@ -1461,37 +1461,12 @@ class Connection(object):
         by returning a 1-element list containing :attr:`python_path` + codecs
 
         This allows emulation of existing tools where the Python invocation may
-        be set to e.g. `['/usr/bin/env', 'python']` or
-        `['source', '/opt/rh/rh-python36/enable, '&&', 'python']`
+        be set to e.g. `['/usr/bin/env', 'python']`
         """
-        # if isinstance(self.options.python_path, list):
-        #     python_path = " ".join(self.options.python_path)
-        # else:
-        #     python_path = self.options.python_path
-
-        # quoting the entire command necessary to invoke python supports
-        # complex python_paths
-        # return ["'" + python_path, '-c',
-        #     'import codecs,os,sys;_=codecs.decode;'
-        #     'exec(_(_("%s".encode(),"base64"),"zip"))\'' % (encoded.decode(),)
-        #         ]
-
         if isinstance(self.options.python_path, list):
             return self.options.python_path
         return [self.options.python_path]
 
-        """
-        return self.get_python_argv() + [
--            '-c',
--            'import codecs,os,sys;_=codecs.decode;'
--            'exec(_(_("%s".encode(),"base64"),"zip"))' % (encoded.decode(),)
--        ]
-
-        if isinstance(self.options.python_path, list):
--            return self.options.python_path
--        return [self.options.python_path]
-        """
-
     def get_boot_command(self):
         source = inspect.getsource(self._first_stage)
         source = textwrap.dedent('\n'.join(source.strip().split('\n')[2:]))
@@ -1507,7 +1482,6 @@ class Connection(object):
         # codecs.decode() requires a bytes object. Since we must be compatible
         # with 2.4 (no bytes literal), an extra .encode() either returns the
         # same str (2.x) or an equivalent bytes (3.x).
-        # return self.get_python_cmd(encoded)
         return self.get_python_argv() + [
             '-c',
             'import codecs,os,sys;_=codecs.decode;'
@@ -1549,8 +1523,6 @@ class Connection(object):
 
     def start_child(self):
         args = self.get_boot_command()
-        LOG.debug('%s', args)
-        LOG.debug('walrus')
         LOG.debug('command line for %r: %s', self, Argv(args))
         try:
             return self.create_child(args=args, **self.create_child_args)
diff --git a/mitogen/ssh.py b/mitogen/ssh.py
index 602581cf..244766c5 100644
--- a/mitogen/ssh.py
+++ b/mitogen/ssh.py
@@ -298,12 +298,10 @@ class Connection(mitogen.parent.Connection):
         if self.options.ssh_args:
             bits += self.options.ssh_args
         bits.append(self.options.hostname)
-        # import pdb
-        # pdb.set_trace()
         base = super(Connection, self).get_boot_command()
+
         base_parts = []
         for s in base:
             val = s if s in self.SHLEX_IGNORE else shlex_quote(s).strip()
             base_parts.append(val)
         return bits + base_parts
-        # return bits + [shlex_quote(s).strip() for s in base]
diff --git a/mitogen/sudo.py b/mitogen/sudo.py
index ea07d0c1..75396fe4 100644
--- a/mitogen/sudo.py
+++ b/mitogen/sudo.py
@@ -114,10 +114,10 @@ SUDO_OPTIONS = [
     #(False, 'bool', '--background', '-b')
     #(False, 'str', '--close-from', '-C')
     #(False, 'str', '--login-class', 'c')
-    (True,  'bool', '--preserve-env', '-E'),
+    (True, 'bool', '--preserve-env', '-E'),
     #(False, 'bool', '--edit', '-e')
     #(False, 'str', '--group', '-g')
-    (True,  'bool', '--set-home', '-H'),
+    (True, 'bool', '--set-home', '-H'),
     #(False, 'str', '--host', '-h')
     (False, 'bool', '--login', '-i'),
     #(False, 'bool', '--remove-timestamp', '-K')
@@ -146,8 +146,10 @@ SUDO_OPTIONS = [
 class OptionParser(optparse.OptionParser):
     def help(self):
         self.exit()
+
     def error(self, msg):
         self.exit(msg=msg)
+
     def exit(self, status=0, msg=None):
         msg = 'sudo: ' + (msg or 'unsupported option')
         raise mitogen.core.StreamError(msg)
@@ -167,7 +169,7 @@ def parse_sudo_flags(args):
     parser = make_sudo_parser()
     opts, args = parser.parse_args(args)
     if len(args):
-        raise mitogen.core.StreamError('unsupported sudo arguments:'+str(args))
+        raise mitogen.core.StreamError('unsupported sudo arguments:' + str(args))
     return opts
 
 
@@ -249,6 +251,12 @@ class Connection(mitogen.parent.Connection):
     }
     child_is_immediate_subprocess = False
 
+    # sudo can't run bash builtins; if a supported builtin is detected
+    # append `-s` to the sudo command to start a shell as the desired user
+    SUPPORTED_BASH_BUILTINS = [
+        "source"
+    ]
+
     def _get_name(self):
         return u'sudo.' + mitogen.core.to_text(self.options.username)
 
@@ -256,6 +264,8 @@ class Connection(mitogen.parent.Connection):
         # Note: sudo did not introduce long-format option processing until July
         # 2013, so even though we parse long-format options, supply short-form
         # to the sudo command.
+        boot_cmd = super(Connection, self).get_boot_command()
+
         bits = [self.options.sudo_path, '-u', self.options.username]
         if self.options.preserve_env:
             bits += ['-E']
@@ -267,5 +277,9 @@ class Connection(mitogen.parent.Connection):
             bits += ['-r', self.options.selinux_role]
         if self.options.selinux_type:
             bits += ['-t', self.options.selinux_type]
+        for builtin in self.SUPPORTED_BASH_BUILTINS:
+            if builtin in boot_cmd:
+                bits += ['-s']
+                break
 
-        return bits + ['--'] + super(Connection, self).get_boot_command()
+        return bits + ['--'] + boot_cmd