Check the PMIx version for min required

Need to check the PMIx version at runtime to ensure it
meets the minimum requirements. Can only do this where
supported (i.e., PMIx v4.2.7 and above).

Signed-off-by: Ralph Castain <rhc@pmix.org>

config/prte_setup_pmix.m4

@@ -120,6 +120,10 @@ AC_DEFUN([PRTE_CHECK_PMIX],[
     PRTE_FLAGS_APPEND_UNIQ(PRTE_FINAL_LDFLAGS, $prte_pmix_LDFLAGS)
     PRTE_FLAGS_APPEND_UNIQ(PRTE_FINAL_LIBS, $prte_pmix_LIBS)
 
+    AC_DEFINE_UNQUOTED([PRTE_PMIX_MINIMUM_VERSION],
+                       [$prte_pmix_min_num_version],
+                       [Minimum supported PMIx version])
+
     found_pmixcc=0
     PMIXCC_PATH="pmixcc"
     AS_IF([test -n "${with_pmix}"],

src/docs/show-help-files/help-prted.rst

@@ -275,15 +275,15 @@ is alive:
 
 [mpir-debugger-detected]
 
-PRTE has detected that you have attached a debugger to this MPI
+PRRTE has detected that you have attached a debugger to this MPI
 job, and that debugger is using the legacy "MPIR" method of
 attachment.
 
-Please note that PRTE has deprecated the "MPIR" debugger
+Please note that PRRTE has deprecated the "MPIR" debugger
 attachment method in favor of the new "PMIx" debugger attchment
 mechanisms.
 
-.. warning:: This means that future versions of PRTE may not support
+.. warning:: This means that future versions of PRRTE may not support
              the "MPIR" debugger attachment method at all.
              Specifically: the debugger you just attached may not work
              with future versions of PRTE.
@@ -305,3 +305,14 @@ set:
 
 Only one of these can be set |mdash| please fix the options and try
 again.
+
+[min-pmix-violation]
+
+PRRTE has detected that the PMIx library being used to run this
+executable does not meet the minimum supported version:
+
+  Min PMIx version: %0x
+  Detected version: %0x
+
+Please check your LD_LIBRARY_PATH and ensure we are pointed to
+a version that meets the minimum requirement.

src/prted/pmix/pmix_server.c

@@ -568,6 +568,7 @@ int pmix_server_init(void)
     pmix_data_array_t darray;
     pmix_info_t *info, myinf;
     size_t n, ninfo;
+    pmix_value_t *val;
     char *tmp;
     pmix_status_t prc;
     prte_pmix_lock_t lock;
@@ -829,6 +830,24 @@ int pmix_server_init(void)
     PMIX_INFO_FREE(info, ninfo);
     rc = PRTE_SUCCESS;
 
+#ifdef PMIX_VERSION_NUMERIC
+    /* find out what version of PMIx is being used - note that
+     * it is NOT an error to not be able to retrieve this
+     * value as it just means the PMIx library pre-dates
+     * introduction of the ability to retrieve the version */
+    prc = PMIx_Get(NULL, PMIX_VERSION_NUMERIC, NULL, 0, &val);
+    if (PMIX_SUCCESS == prc) {
+        // check the version
+        if (val->data.uint32 < PRTE_PMIX_MINIMUM_VERSION) {
+            pmix_show_help("help-prted.txt", "min-pmix-violation", true,
+                           PRTE_PMIX_MINIMUM_VERSION, val->data.uint32);
+            PMIX_VALUE_RELEASE(val);
+            return PRTE_ERR_SILENT;
+        }
+        PMIX_VALUE_RELEASE(val);
+    }
+#endif
+
     /* register our support */
     for (n = 0; 0 != strlen(prte_attributes[n].function); n++) {
         prc = PMIx_Register_attributes(prte_attributes[n].function, prte_attributes[n].attrs);