diff -r 34020d1f1635 -r c6a3243567b6 mercurial/cext/osutil.c
--- a/mercurial/cext/osutil.c	Mon Jun 06 13:58:32 2022 +0400
+++ b/mercurial/cext/osutil.c	Thu Jun 02 23:57:56 2022 +0200
@@ -685,75 +685,6 @@
 	return NULL;
 }
 
-/*
- * recvfds() simply does not release GIL during blocking io operation because
- * command server is known to be single-threaded.
- *
- * Old systems such as Solaris don't provide CMSG_LEN, msg_control, etc.
- * Currently, recvfds() is not supported on these platforms.
- */
-#ifdef CMSG_LEN
-
-static ssize_t recvfdstobuf(int sockfd, int **rfds, void *cbuf, size_t cbufsize)
-{
-	char dummy[1];
-	struct iovec iov = {dummy, sizeof(dummy)};
-	struct msghdr msgh = {0};
-	struct cmsghdr *cmsg;
-
-	msgh.msg_iov = &iov;
-	msgh.msg_iovlen = 1;
-	msgh.msg_control = cbuf;
-	msgh.msg_controllen = (socklen_t)cbufsize;
-	if (recvmsg(sockfd, &msgh, 0) < 0)
-		return -1;
-
-	for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg;
-	     cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
-		if (cmsg->cmsg_level != SOL_SOCKET ||
-		    cmsg->cmsg_type != SCM_RIGHTS)
-			continue;
-		*rfds = (int *)CMSG_DATA(cmsg);
-		return (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
-	}
-
-	*rfds = cbuf;
-	return 0;
-}
-
-static PyObject *recvfds(PyObject *self, PyObject *args)
-{
-	int sockfd;
-	int *rfds = NULL;
-	ssize_t rfdscount, i;
-	char cbuf[256];
-	PyObject *rfdslist = NULL;
-
-	if (!PyArg_ParseTuple(args, "i", &sockfd))
-		return NULL;
-
-	rfdscount = recvfdstobuf(sockfd, &rfds, cbuf, sizeof(cbuf));
-	if (rfdscount < 0)
-		return PyErr_SetFromErrno(PyExc_OSError);
-
-	rfdslist = PyList_New(rfdscount);
-	if (!rfdslist)
-		goto bail;
-	for (i = 0; i < rfdscount; i++) {
-		PyObject *obj = PyLong_FromLong(rfds[i]);
-		if (!obj)
-			goto bail;
-		PyList_SET_ITEM(rfdslist, i, obj);
-	}
-	return rfdslist;
-
-bail:
-	Py_XDECREF(rfdslist);
-	return NULL;
-}
-
-#endif /* CMSG_LEN */
-
 /* allow disabling setprocname via compiler flags */
 #ifndef SETPROCNAME_USE_NONE
 #if defined(HAVE_SETPROCTITLE)
@@ -1285,10 +1216,6 @@
 	{"statfiles", (PyCFunction)statfiles, METH_VARARGS | METH_KEYWORDS,
 	 "stat a series of files or symlinks\n"
 "Returns None for non-existent entries and entries of other types.\n"},
-#ifdef CMSG_LEN
-	{"recvfds", (PyCFunction)recvfds, METH_VARARGS,
-	 "receive list of file descriptors via socket\n"},
-#endif
 #ifndef SETPROCNAME_USE_NONE
 	{"setprocname", (PyCFunction)setprocname, METH_VARARGS,
 	 "set process title (best-effort)\n"},