pmix.nodeid tests fail on openmpix 4.2

[grondo]

When updating the project Dockerfile to use the el8 image instead of centos8, it appeared that the v5.0.x openmpi branch now requires openmpix-4.2.

*** Configuring PMIx
checking for pmix pkg-config name... pmix
checking if pmix pkg-config module exists... yes
checking for pmix pkg-config cflags... 
checking for pmix pkg-config ldflags... 
checking for pmix pkg-config static ldflags... 
checking for pmix pkg-config libs... -lpmix -lhwloc -levent -lz 
checking for pmix pkg-config static libs... -lpmix -lhwloc -lm -ldl -lpthread -levent -lcrypto -lz 
checking pmix.h usability... yes
checking pmix.h presence... yes
checking for pmix.h... yes
checking for PMIx_Init... yes
checking if pmix requires libnl v1 or v3... none
checking if external PMIx version is 4.1.2 or greater... no
configure: error: External PMIx requested but not found.

Updating to that version, however triggers failures in pmix.nodeid.

Changes to Dockerfile to reproduce:

diff --git a/src/test/docker/el8/Dockerfile b/src/test/docker/el8/Dockerfile
index cae69e1..74a6165 100644
--- a/src/test/docker/el8/Dockerfile
+++ b/src/test/docker/el8/Dockerfile
@@ -1,9 +1,9 @@
-FROM fluxrm/flux-core:centos8
+FROM fluxrm/flux-core:el8

 ARG USER=fluxuser
 ARG UID=1000
 ARG OMPI_BRANCH=v5.0.x
-ARG OPENPMIX_BRANCH=v4.1.1rc2
+ARG OPENPMIX_BRANCH=v4.2

 RUN \
  if test "$USER" != "fluxuser"; then  \

expecting success: 
    cat >2n3p.pmix.nodeid.exp <<-EOT &&
    0: 0
    1: 0
    2: 1
    EOT
    run_timeout 30 flux mini run -N2 -n3 \
        ${GETKEY} --label-io pmix.nodeid \
            | sort -n >2n3p.pmix.nodeid.out &&
    test_cmp 2n3p.pmix.nodeid.exp 2n3p.pmix.nodeid.out

f4nALqDZ.2: PMIx_Get pmix.nodeid: NOT-FOUND
f4nALqDZ.0: PMIx_Get pmix.nodeid: NOT-FOUND
f4nALqDZ.1: PMIx_Get pmix.nodeid: NOT-FOUND
flux-job: task(s) exited with exit code 1
--- 2n3p.pmix.nodeid.exp    2022-07-01 02:55:55.177460840 +0000
+++ 2n3p.pmix.nodeid.out    2022-07-01 02:55:55.177460840 +0000
@@ -1,3 +0,0 @@
-0: 0
-1: 0
-2: 1
not ok 18 - 2n3p pmix.nodeid is set correctly
#   
#       cat >2n3p.pmix.nodeid.exp <<-EOT &&
#       0: 0
#       1: 0
#       2: 1
#       EOT
#       run_timeout 30 flux mini run -N2 -n3 \
#           ${GETKEY} --label-io pmix.nodeid \
#               | sort -n >2n3p.pmix.nodeid.out &&
#       test_cmp 2n3p.pmix.nodeid.exp 2n3p.pmix.nodeid.out
#   

expecting success: 
    cat >pmix.nodeid.exp <<-EOT &&
    0: 0
    1: 0
    2: 1
    3: 1
    EOT
    run_timeout 30 flux mini run -N2 -n4 \
        ${GETKEY} --label-io pmix.nodeid \
            | sort -n >pmix.nodeid.out &&
    test_cmp pmix.nodeid.exp pmix.nodeid.out

f52wFg6s.0: PMIx_Get pmix.nodeid: NOT-FOUND
f52wFg6s.2: PMIx_Get pmix.nodeid: NOT-FOUND
f52wFg6s.3: PMIx_Get pmix.nodeid: NOT-FOUND
f52wFg6s.1: PMIx_Get pmix.nodeid: NOT-FOUND
flux-job: task(s) exited with exit code 1
--- pmix.nodeid.exp 2022-07-01 02:55:55.737465873 +0000
+++ pmix.nodeid.out 2022-07-01 02:55:55.741465909 +0000
@@ -1,4 +0,0 @@
-0: 0
-1: 0
-2: 1
-3: 1
not ok 19 - 2n4p pmix.nodeid is set correctly
#   
#       cat >pmix.nodeid.exp <<-EOT &&
#       0: 0
#       1: 0
#       2: 1
#       3: 1
#       EOT
#       run_timeout 30 flux mini run -N2 -n4 \
#           ${GETKEY} --label-io pmix.nodeid \
#               | sort -n >pmix.nodeid.out &&
#       test_cmp pmix.nodeid.exp pmix.nodeid.out
#