bpo-38778: Document that os.fork is not allowed in subinterpreters (GH-17123)

phmc · miss-islington · commit b22030073b93 · 2019-11-15T08:56:03.000-08:00
Small docs update for [bpo-34651](https://bugs.python.org/issue34651). Other references to fork (e.g. the PyOS.*Fork functions or discussions of fork() when embedding Python) point back to os.fork, so I don't think any other updates are needed. https://bugs.python.org/issue38778 Automerge-Triggered-By: @ericsnowcurrently
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
@@ -3478,7 +3478,11 @@ written in Python, such as a mail server's external command delivery program.
    parent.  If an error occurs :exc:`OSError` is raised.
 
    Note that some platforms including FreeBSD <= 6.3 and Cygwin have
-   known issues when using fork() from a thread.
+   known issues when using ``fork()`` from a thread.
+
+   .. versionchanged:: 3.8
+      Calling ``fork()`` in a subinterpreter is no longer supported
+      (:exc:`RuntimeError` is raised).
 
    .. warning::
 
@@ -3495,6 +3499,10 @@ written in Python, such as a mail server's external command delivery program.
    master end of the pseudo-terminal.  For a more portable approach, use the
    :mod:`pty` module.  If an error occurs :exc:`OSError` is raised.
 
+   .. versionchanged:: 3.8
+      Calling ``forkpty()`` in a subinterpreter is no longer supported
+      (:exc:`RuntimeError` is raised).
+
    .. availability:: some flavors of Unix.
 
 
diff --git a/Misc/NEWS.d/next/Documentation/2019-11-12-15-31-09.bpo-38778.PHhTlv.rst b/Misc/NEWS.d/next/Documentation/2019-11-12-15-31-09.bpo-38778.PHhTlv.rst
@@ -0,0 +1 @@
+Document the fact that :exc:`RuntimeError` is raised if :meth:`os.fork` is called in a subinterpreter.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Document the fact that :exc:`RuntimeError` is raised if :meth:`os.fork` is called in a subinterpreter.