diff --git a/src/buildstream/element.py b/src/buildstream/element.py
index c67f886..ee3b2fc 100644
--- a/src/buildstream/element.py
+++ b/src/buildstream/element.py
@@ -83,7 +83,7 @@
 from functools import partial
 from itertools import chain
 import string
-from typing import cast, TYPE_CHECKING, Any, Dict, Iterator, List, Optional, Set, Sequence
+from typing import cast, TYPE_CHECKING, Any, Dict, Iterator, Iterable, List, Optional, Set, Sequence
 
 from pyroaring import BitMap  # pylint: disable=no-name-in-module
 from ruamel import yaml
@@ -328,7 +328,7 @@
     #############################################################
     #                      Abstract Methods                     #
     #############################################################
-    def configure_dependencies(self, dependencies: List[DependencyConfiguration]) -> None:
+    def configure_dependencies(self, dependencies: Iterable[DependencyConfiguration]) -> None:
         """Configure the Element with regards to it's build dependencies
 
         Elements can use this method to parse custom configuration which define their
@@ -824,7 +824,7 @@
         """ Configure command batching across prepare() and assemble()
 
         Args:
-           flags: The sandbox flags for the command batch
+           flags: The :class:`.SandboxFlags` for the command batch
            collect: An optional directory containing partial install contents
                     on command failure.
 
diff --git a/src/buildstream/plugin.py b/src/buildstream/plugin.py
index 4008734..6a8b221 100644
--- a/src/buildstream/plugin.py
+++ b/src/buildstream/plugin.py
@@ -133,7 +133,7 @@
 import sys
 import traceback
 from contextlib import contextmanager, suppress
-from typing import Any, Callable, Generator, Optional, Sequence, Tuple, TypeVar, TYPE_CHECKING
+from typing import IO, Any, Callable, Generator, Optional, Sequence, Dict, Tuple, TypeVar, Union, TYPE_CHECKING
 from weakref import WeakValueDictionary
 
 from . import utils, _signals
@@ -152,6 +152,22 @@
 
 T1 = TypeVar("T1")
 
+#
+# Some types used for subprocess.Popen() wrappers
+#
+# This recipe was gleaned from observing:
+#    https://github.com/python/typeshed/blob/master/stdlib/_typeshed/__init__.pyi
+#    https://github.com/python/typeshed/blob/master/stdlib/subprocess.pyi
+#
+_FILE = Union[None, int, IO[Any]]
+_TXT = Union[bytes, str]
+_STR_BYTES_PATH = Union[str, bytes, "os.PathLike[str]", "os.PathLike[bytes]"]
+if sys.version_info >= (3, 8):
+    _CMD = Union[_STR_BYTES_PATH, Sequence[_STR_BYTES_PATH]]
+else:
+    # Python 3.6 doesn't support _CMD being a single PathLike.
+    # See: https://bugs.python.org/issue31961
+    _CMD = Union[_TXT, Sequence[_STR_BYTES_PATH]]
 
 # _background_job_wrapper()
 #
@@ -664,16 +680,28 @@
 
             return result
 
-    def call(self, *popenargs, fail: Optional[str] = None, fail_temporarily: bool = False, **kwargs) -> int:
+    def call(
+        self,
+        args: _CMD,
+        fail: Optional[str] = None,
+        fail_temporarily: bool = False,
+        cwd: Optional[_STR_BYTES_PATH] = None,
+        env: Optional[Dict[str, str]] = None,
+        stdin: Optional[_FILE] = None,
+        stdout: Optional[_FILE] = None,
+        stderr: Optional[_FILE] = None,
+    ) -> int:
         """A wrapper for subprocess.call()
 
         Args:
-           popenargs (list): Popen() arguments
-           fail: A message to display if the process returns
-                 a non zero exit code
-           fail_temporarily: Whether any exceptions should
-                             be raised as temporary.
-           rest_of_args (kwargs): Remaining arguments to subprocess.call()
+           args: A sequence of program arguments or else a string or `path-like-object <https://docs.python.org/3/glossary.html#term-path-like-object>`_
+           fail: A message to display if the process returns a non zero exit code
+           fail_temporarily: Whether any exceptions should be raised as temporary.
+           cwd: Optionally specify the working directory for the command
+           env: Optionally specify some environment variables for the command
+           stdin: Optionally specify standard input for the command
+           stdout: Optionally specify standard output for the command
+           stderr: Optionally specify standard error for the command
 
         Returns:
            The process exit code.
@@ -681,8 +709,15 @@
         Raises:
            (:class:`.PluginError`): If a non-zero return code is received and *fail* is specified
 
-        Note: If *fail* is not specified, then the return value of subprocess.call()
-              is returned even on error, and no exception is automatically raised.
+        .. attention::
+
+          If *fail* is not specified, then the return value of subprocess.call()
+          is returned even on error, and no exception is automatically raised.
+
+        .. attention::
+
+          If *stderr* and/or *stdout* are specified, then these streams are delivered
+          directly to the plugin instead of being delivered to the associated log file.
 
         **Example**
 
@@ -695,19 +730,38 @@
               "Failed to download ponies from {}".format(
                   self.mirror_directory))
         """
-        exit_code, _ = self.__call(*popenargs, fail=fail, fail_temporarily=fail_temporarily, **kwargs)
+        exit_code, _ = self.__call(
+            args,
+            fail=fail,
+            fail_temporarily=fail_temporarily,
+            cwd=cwd,
+            env=env,
+            stdin=stdin,
+            stdout=stdout,
+            stderr=stderr,
+        )
         return exit_code
 
-    def check_output(self, *popenargs, fail=None, fail_temporarily=False, **kwargs) -> Tuple[int, str]:
+    def check_output(
+        self,
+        args: _CMD,
+        fail: Optional[str] = None,
+        fail_temporarily: bool = False,
+        cwd: Optional[_STR_BYTES_PATH] = None,
+        env: Optional[Dict[str, str]] = None,
+        stdin: Optional[_FILE] = None,
+        stderr: Optional[_FILE] = None,
+    ) -> Tuple[int, str]:
         """A wrapper for subprocess.check_output()
 
         Args:
-           popenargs (list): Popen() arguments
-           fail (str): A message to display if the process returns
-                       a non zero exit code
-           fail_temporarily (bool): Whether any exceptions should
-                                    be raised as temporary.
-           rest_of_args (kwargs): Remaining arguments to subprocess.call()
+           args: A sequence of program arguments or else a string or `path-like-object <https://docs.python.org/3/glossary.html#term-path-like-object>`_
+           fail: A message to display if the process returns a non zero exit code
+           fail_temporarily: Whether any exceptions should be raised as temporary.
+           cwd: Optionally specify the working directory for the command
+           env: Optionally specify some environment variables for the command
+           stdin: Optionally specify standard input for the command
+           stderr: Optionally specify standard error for the command
 
         Returns:
            A 2-tuple of form (process exit code, process standard output)
@@ -715,8 +769,15 @@
         Raises:
            (:class:`.PluginError`): If a non-zero return code is received and *fail* is specified
 
-        Note: If *fail* is not specified, then the return value of subprocess.check_output()
-              is returned even on error, and no exception is automatically raised.
+        .. attention::
+
+          If *fail* is not specified, then the return value of subprocess.call()
+          is returned even on error, and no exception is automatically raised.
+
+        .. attention::
+
+          If *stderr* and/or *stdout* are specified, then these streams are delivered
+          directly to the plugin instead of being delivered to the associated log file.
 
         **Example**
 
@@ -744,7 +805,16 @@
               raise SourceError(
                   fmt.format(plugin=self, track=tracking)) from e
         """
-        return self.__call(*popenargs, collect_stdout=True, fail=fail, fail_temporarily=fail_temporarily, **kwargs)
+        return self.__call(
+            args,
+            collect_stdout=True,
+            fail=fail,
+            fail_temporarily=fail_temporarily,
+            cwd=cwd,
+            env=env,
+            stdin=stdin,
+            stderr=stderr,
+        )
 
     #############################################################
     #            Private Methods used in BuildStream            #
@@ -860,19 +930,29 @@
 
     # Internal subprocess implementation for the call() and check_output() APIs
     #
-    def __call(self, *popenargs, collect_stdout=False, fail=None, fail_temporarily=False, **kwargs):
-
+    def __call(
+        self,
+        args: _CMD,
+        fail: Optional[str] = None,
+        fail_temporarily: bool = False,
+        collect_stdout: bool = False,
+        cwd: Optional[_STR_BYTES_PATH] = None,
+        env: Optional[Dict[str, str]] = None,
+        stdin: Optional[_FILE] = None,
+        stdout: Optional[_FILE] = None,
+        stderr: Optional[_FILE] = None,
+    ):
         with self._output_file() as output_file:
-            if "stdout" not in kwargs:
-                kwargs["stdout"] = output_file
-            if "stderr" not in kwargs:
-                kwargs["stderr"] = output_file
+            if stdout is None:
+                stdout = output_file
+            if stderr is None:
+                stderr = output_file
             if collect_stdout:
-                kwargs["stdout"] = subprocess.PIPE
+                stdout = subprocess.PIPE
 
-            self.__note_command(output_file, *popenargs, **kwargs)
+            self.__note_command(output_file, args, cwd)
 
-            exit_code, output = utils._call(*popenargs, **kwargs)
+            exit_code, output = utils._call(args, cwd=cwd, env=env, stdin=stdin, stdout=stdout, stderr=stderr)
 
             if fail and exit_code:
                 raise PluginError("{plugin}: {message}".format(plugin=self, message=fail), temporary=fail_temporarily)
@@ -899,9 +979,18 @@
         message = Message(message_type, brief, **plugin_kwargs)
         self.__context.messenger.message(message)
 
-    def __note_command(self, output, *popenargs, **kwargs):
-        workdir = kwargs.get("cwd", os.getcwd())
-        command = " ".join(popenargs[0])
+    # __note_command():
+    #
+    # Make a note in the logs that we are running a process on the host.
+    #
+    # Args:
+    #    output: The output logging file
+    #    args: The command with args which we're about to run
+    #    cwd: The host side working directory to run the command, or None
+    #
+    def __note_command(self, output, args, cwd):
+        workdir = cwd or os.getcwd()
+        command = " ".join(args)
         output.write("Running host command {}: {}\n".format(workdir, command))
         output.flush()
         self.status("Running host command", detail=command)