Fixes <https://issues.guix.gnu.org/47867>.

This fix was merged upstream
in <https://gitlab.com/gnutls/gnutls/-/merge_requests/1417> and will
be in GnuTLS 3.7.3.  Upstream commit:

commit 110e2172dbef1fbdf7399dab1e80780847b61c0c
Author: Ludovic Courtès <ludo@gnu.org>
Date:   Sat Apr 24 22:02:14 2021 +0200

    guile: Writes to record ports handle EAGAIN/EINTR transparently.

diff --git a/guile/src/core.c b/guile/src/core.c
index a13670fc7b..0926dc8a97 100644
--- a/guile/src/core.c
+++ b/guile/src/core.c
@@ -985,7 +985,10 @@ write_to_session_record_port (SCM port, const void *data, size_t size)
       c_result = gnutls_record_send (c_session, (char *) data + c_sent,
                                      size - c_sent);
       if (EXPECT_FALSE (c_result < 0))
-        scm_gnutls_error (c_result, FUNC_NAME);
+	{
+	  if (c_result != GNUTLS_E_AGAIN && c_result != GNUTLS_E_INTERRUPTED)
+	    scm_gnutls_error (c_result, FUNC_NAME);
+	}
       else
         c_sent += c_result;
     }
@@ -1069,7 +1072,8 @@ read_from_session_record_port (SCM port, SCM dst, size_t start, size_t count)
 #undef FUNC_NAME
 
 /* Return the file descriptor that backs PORT.  This function is called upon a
-   blocking read--i.e., 'read_from_session_record_port' returned -1.  */
+   blocking read--i.e., 'read_from_session_record_port' or
+   'write_to_session_record_port' returned -1.  */
 static int
 session_record_port_fd (SCM port)
 {
@@ -1097,7 +1101,16 @@ write_to_session_record_port (SCM port, SCM src, size_t start, size_t count)
   c_session = scm_to_gnutls_session (session, 1, FUNC_NAME);
   data = (char *) SCM_BYTEVECTOR_CONTENTS (src) + start;
 
-  result = gnutls_record_send (c_session, data, count);
+  do
+    result = gnutls_record_send (c_session, data, count);
+  while (result == GNUTLS_E_INTERRUPTED
+	 || (result == GNUTLS_E_AGAIN
+	     && !SCM_GNUTLS_SESSION_TRANSPORT_IS_FD (c_session)));
+
+  if (result == GNUTLS_E_AGAIN
+      && SCM_GNUTLS_SESSION_TRANSPORT_IS_FD (c_session))
+    /* Tell Guile that reading would block.  */
+    return (size_t) -1;
 
   if (EXPECT_FALSE (result < 0))
     scm_gnutls_error (result, FUNC_NAME);
nu</a>/<a href='/guix/log/gnu/machine?id=861866bef31151da248ba8dcc3aaf8916980ecb5'>machine</a>/<a href='/guix/log/gnu/machine/ssh.scm?id=861866bef31151da248ba8dcc3aaf8916980ecb5'>ssh.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/machine/ssh.scm?id=861866bef31151da248ba8dcc3aaf8916980ecb5&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-08-11 02:00:00 +0200'>2024-08-11</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=902b15b24d6ea2a1e255b88dff7670e8a95cb9a9'>gnu: Replace (almost) all uses of /run/setuid-programs.</a><span class='msg-avail'>...<span class='msg-tooltip'>…those good for master, anyway.

* gnu/packages/admin.scm (ktsuss, opendoas, hosts)
[arguments]: Replace /run/setuid-programs with /run/privileged/bin.
* gnu/packages/containers.scm (slirp4netns)[arguments]: Likewise.
* gnu/packages/debian.scm (pbuilder)[arguments]: Likewise.
* gnu/packages/disk.scm (udevil)[arguments]: Likewise.
* gnu/packages/enlightenment.scm (efl, enlightenment)
[arguments]: Likewise.
* gnu/packages/gnome.scm (gdm, gnome-control-center)
[arguments]: Likewise.
* gnu/packages/linux.scm (singularity)[arguments]: Likewise.
* gnu/packages/lxde.scm (spacefm)[arguments]: Likewise.
* gnu/packages/monitoring.scm (zabbix-agentd)[arguments]: Likewise.
* gnu/packages/virtualization.scm (ganeti)[arguments]: Likewise.
* gnu/packages/xdisorg.scm (xsecurelock)[arguments]: Likewise.
* gnu/services/dbus.scm (dbus-configuration-directory): Likewise.
* gnu/services/ganeti.scm (%default-ganeti-environment-variables):
Likewise.
* gnu/services/monitoring.scm (zabbix-agent-shepherd-service): Likewise.
* gnu/tests/ldap.scm (marionette): Likewise.
* gnu/tests/monitoring.scm (os): Likewise.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2024-06-04 12:08:34 +0200'>2024-06-04</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=3e87b207ce96679e2f289a5522a248d38c4f3962'>file-systems: Add support for mounting CIFS file systems</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/file-systems (canonicalize-device-name): Do not attempt to resolve
CIFS formatted device specifications.
(mount-file-systems): Add mount-cifs nested function.
* gnu/machine/ssh.scm (machine-check-file-system-availability): Skip checking
for CIFS availability, similar to NFS.
* guix/scripts/system.scm (check-file-system-availability): Likewise.

Change-Id: I182e290eba64bbe5d1332815eb93bb68c01e0c3c
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Richard Sent</td></tr>
<tr><td><span title='2024-02-19 11:21:27 +0100'>2024-02-19</span></td><td><a href='/guix/commit/gnu/machine/ssh.scm?id=9ce548a26e59d85ad9341c0212fef38392d49ff4'>machine/ssh: Refresh parameterization of %CURRENT-SYSTEM.</a><span class='msg-avail'>...<span class='msg-tooltip'>When using "guix deploy" on an x86_64-linux machine to deploy a system to
i686-linux, DEPLOY-MANAGED-HOST would revert %CURRENT-SYSTEM to the host
system's value by the time it evaluated UPGRADE-SHEPHERD-SERVICES.  The
earlier PARAMETERIZE would no longer be effective.

* gnu/machine/ssh.scm (deploy-managed-host): Ensure that
UPGRADE-SHEPHERD-SERVICES is evaluated for the architecture of the target
machine.

Change-Id: I0816da79cd7c46a69418717fa33b2fe4e2fabae0
</span></span></td><td>Ricardo Wurmus</td></tr>