diff --git a/config/ompi_setup_prrte.m4 b/config/ompi_setup_prrte.m4
index 3871440a0f5..a83bd618f71 100644
--- a/config/ompi_setup_prrte.m4
+++ b/config/ompi_setup_prrte.m4
@@ -46,6 +46,15 @@ AC_DEFUN([OMPI_SETUP_PRRTE],[
         [AC_HELP_STRING([--enable-prte-prefix-by-default],
             [Make "mpirun ..." behave exactly the same as "mpirun --prefix \$prefix" (where \$prefix is the value given to --prefix in configure) (default:enabled)])])
 
+    AS_IF([test "$opal_external_pmix_happy" = "yes" && test $opal_numerical_pmix_version -lt 4 && test "$enable_internal_rte" != "no"],
+          [AC_MSG_WARN([OMPI's internal runtime environment "PRRTE" does not support])
+           AC_MSG_WARN([PMIx versions less than v4.x as they lack adequate tool])
+           AC_MSG_WARN([support. You can, if desired, build OMPI against an earlier])
+           AC_MSG_WARN([version of PMIx for strictly direct-launch purposes - e.g., using)])
+           AC_MSG_WARN([Slurm's srun to launch the job - by configuring with the])
+           AC_MSG_WARN([--disable-internal-rte option.])
+           AC_MSG_ERROR([Cannot continue])])
+
     AC_MSG_CHECKING([if RTE support is enabled])
     if test "$enable_internal_rte" != "no"; then
         AC_MSG_RESULT([yes])
@@ -81,7 +90,7 @@ AC_DEFUN([OMPI_SETUP_PRRTE],[
             opal_prrte_prefix_arg=
         fi
 
-        opal_prrte_args="--prefix=$prefix --disable-dlopen $opal_prrte_prefix_arg $opal_prrte_libevent_arg $opal_prrte_hwloc_arg $opal_prrte_pmix_arg"
+        opal_prrte_args="--prefix=$prefix $opal_prrte_prefix_arg $opal_prrte_libevent_arg $opal_prrte_hwloc_arg $opal_prrte_pmix_arg"
         AS_IF([test "$enable_debug" = "yes"],
               [opal_prrte_args="--enable-debug $opal_prrte_args"
                CFLAGS="$OPAL_CFLAGS_BEFORE_PICKY $OPAL_VISIBILITY_CFLAGS -g"],
diff --git a/config/opal_check_pmi.m4 b/config/opal_check_pmi.m4
index c5706f4bffe..6f18c02cd1c 100644
--- a/config/opal_check_pmi.m4
+++ b/config/opal_check_pmi.m4
@@ -125,6 +125,7 @@ AC_DEFUN([OPAL_CHECK_PMIX_LIB],[
                                                     ], [])],
                                     [AC_MSG_RESULT([found])
                                      opal_external_pmix_version=4x
+                                     opal_numerical_pmix_version=4
                                      opal_external_pmix_version_found=1
                                      opal_external_pmix_happy=yes],
                                     [AC_MSG_RESULT([not found])])])
@@ -139,6 +140,7 @@ AC_DEFUN([OPAL_CHECK_PMIX_LIB],[
                                               ], [])],
                                    [AC_MSG_RESULT([found])
                                     opal_external_pmix_version=3x
+                                    opal_numerical_pmix_version=3
                                     opal_external_pmix_version_found=1
                                     opal_external_pmix_happy=yes],
                                    [AC_MSG_RESULT([not found])])])
@@ -153,6 +155,7 @@ AC_DEFUN([OPAL_CHECK_PMIX_LIB],[
                                               ], [])],
                                    [AC_MSG_RESULT([found])
                                     opal_external_pmix_version=2x
+                                    opal_numerical_pmix_version=2
                                     opal_external_pmix_version_found=1
                                     opal_external_pmix_happy=yes],
                                    [AC_MSG_RESULT([not found])])])
@@ -167,6 +170,7 @@ AC_DEFUN([OPAL_CHECK_PMIX_LIB],[
                                               ], [])],
                                    [AC_MSG_RESULT([found])
                                     opal_external_pmix_version=1x
+                                    opal_numerical_pmix_version=1
                                     opal_external_pmix_version_found=1
                                     opal_external_have_pmix1=1
                                     opal_external_pmix_happy=yes],
@@ -179,6 +183,12 @@ AC_DEFUN([OPAL_CHECK_PMIX_LIB],[
                  opal_external_pmix_happy=no])
 
     ])
+    AS_IF([test "$opal_external_pmix_happy" = "yes" && test $opal_numerical_pmix_version -lt 3],
+          [AC_MSG_WARN([OMPI no longer supports PMIx versions prior to v3])
+           AC_MSG_WARN([Please direct us to a more current PMIx release or])
+           AC_MSG_WARN([use the internally provided one])
+           AC_MSG_ERROR([Cannot continue])])
+
     AS_IF([test "$opal_external_pmix_happy" = "yes"],
           [$3
            # add the new flags to our wrapper compilers
diff --git a/ompi/interlib/interlib.c b/ompi/interlib/interlib.c
index 69062c5de37..da18b694199 100644
--- a/ompi/interlib/interlib.c
+++ b/ompi/interlib/interlib.c
@@ -121,6 +121,10 @@ int ompi_interlib_declare(int threadlevel, char *version)
     PMIX_INFO_DESTRUCT(&info[3]);
     /* account for our refcount on pmix_init */
     PMIx_Finalize(NULL, 0);
-    ret = opal_pmix_convert_status(rc);
+    if (ompi_singleton && PMIX_ERR_UNREACH == rc) {
+        ret = OMPI_SUCCESS;
+    } else {
+        ret = opal_pmix_convert_status(rc);
+    }
     return ret;
 }
diff --git a/ompi/runtime/ompi_mpi_abort.c b/ompi/runtime/ompi_mpi_abort.c
index a550e7b9f65..a42109b5de5 100644
--- a/ompi/runtime/ompi_mpi_abort.c
+++ b/ompi/runtime/ompi_mpi_abort.c
@@ -85,8 +85,8 @@ static void try_kill_peers(ompi_communicator_t *comm,
 
     procs = (ompi_process_name_t*) calloc(nprocs, sizeof(ompi_process_name_t));
     if (NULL == procs) {
-        /* quick clean orte and get out */
-        ompi_rte_abort(errno, "Abort: unable to alloc memory to kill procs");
+        /* quick clean RTE and get out */
+        ompi_rte_abort(errcode, "Abort: unable to alloc memory to kill procs");
     }
 
     /* put all the local group procs in the abort list */
diff --git a/ompi/runtime/ompi_rte.c b/ompi/runtime/ompi_rte.c
index 66a2db21edb..d459024231d 100644
--- a/ompi/runtime/ompi_rte.c
+++ b/ompi/runtime/ompi_rte.c
@@ -61,7 +61,27 @@
 opal_process_name_t pmix_name_wildcard = {UINT32_MAX-1, UINT32_MAX-1};
 opal_process_name_t pmix_name_invalid = {UINT32_MAX, UINT32_MAX};
 hwloc_cpuset_t ompi_proc_applied_binding = NULL;
-pmix_process_info_t pmix_process_info = {0};
+pmix_process_info_t pmix_process_info = {
+    .my_name = {OPAL_JOBID_INVALID, OPAL_VPID_INVALID},
+    .nodename = NULL,
+    .pid = 0,
+    .top_session_dir = NULL,
+    .job_session_dir = NULL,
+    .proc_session_dir = NULL,
+    .my_local_rank = 0,
+    .my_node_rank = 0,
+    .num_local_peers = 0,
+    .num_procs = 0,
+    .app_num = 0,
+    .univ_size = 0,
+    .app_sizes = NULL,
+    .app_ldrs = NULL,
+    .cpuset = NULL,
+    .command = NULL,
+    .num_apps = 0,
+    .initial_wdir = NULL,
+    .reincarnation = 0
+};
 bool pmix_proc_is_bound = false;
 bool ompi_singleton = false;
 
diff --git a/opal/mca/pmix/pmix4x/openpmix b/opal/mca/pmix/pmix4x/openpmix
index 98d14d55f8d..a18e5313829 160000
--- a/opal/mca/pmix/pmix4x/openpmix
+++ b/opal/mca/pmix/pmix4x/openpmix
@@ -1 +1 @@
-Subproject commit 98d14d55f8d4bd27fe6eb1e508c336702e1fbf76
+Subproject commit a18e53138298d61a01fec4471518140304539e8c
diff --git a/opal/mca/rcache/grdma/rcache_grdma_module.c b/opal/mca/rcache/grdma/rcache_grdma_module.c
index c4e72c00415..3f163c2d7f1 100644
--- a/opal/mca/rcache/grdma/rcache_grdma_module.c
+++ b/opal/mca/rcache/grdma/rcache_grdma_module.c
@@ -187,7 +187,7 @@ static inline mca_rcache_base_registration_t *mca_rcache_grdma_remove_lru_head(m
             /* registration has been selected for removal and is no longer in the LRU. mark it
              * as such. */
             new_flags = (old_flags & ~MCA_RCACHE_GRDMA_REG_FLAG_IN_LRU) | MCA_RCACHE_FLAGS_INVALID;
-            if (opal_atomic_compare_exchange_strong_32(&old_reg->flags, &old_flags, new_flags)) {
+            if (opal_atomic_compare_exchange_strong_32((opal_atomic_int32_t*)&old_reg->flags, &old_flags, new_flags)) {
                 break;
             }
         } while (1);
diff --git a/opal/runtime/opal_init.c b/opal/runtime/opal_init.c
index ab17e8e9bb7..09e10a4fd57 100644
--- a/opal/runtime/opal_init.c
+++ b/opal/runtime/opal_init.c
@@ -54,6 +54,7 @@
 #include "opal/mca/installdirs/base/base.h"
 #include "opal/mca/memory/base/base.h"
 #include "opal/mca/patcher/base/base.h"
+#include "opal/mca/pmix/base/base.h"
 #include "opal/mca/memcpy/base/base.h"
 #include "opal/mca/hwloc/base/base.h"
 #include "opal/mca/reachable/base/base.h"
@@ -630,7 +631,7 @@ opal_init_util(int* pargc, char*** pargv)
 static mca_base_framework_t *opal_init_frameworks[] = {
     &opal_hwloc_base_framework, &opal_memcpy_base_framework, &opal_memchecker_base_framework,
     &opal_backtrace_base_framework, &opal_timer_base_framework, &opal_event_base_framework,
-    &opal_shmem_base_framework, &opal_reachable_base_framework,
+    &opal_shmem_base_framework, &opal_reachable_base_framework, &opal_pmix_base_framework,
     NULL,
 };
 
diff --git a/prrte b/prrte
index 9add90bcfe8..cdea5231171 160000
--- a/prrte
+++ b/prrte
@@ -1 +1 @@
-Subproject commit 9add90bcfe88af1994914a78544d6236327be10e
+Subproject commit cdea5231171b2fdea11269033de9e265fc7f3a63