From 05bdcea1763e12ea82996bb2b4fa0bfb2fe5dcdf Mon Sep 17 00:00:00 2001
From: Bill Sacks <sacks@ucar.edu>
Date: Sat, 8 Nov 2025 05:56:10 -0700
Subject: [PATCH 1/2] Add a system test that runs the CESM_share unit tests

Requires the CIME changes in https://github.com/ESMCI/cime/pull/4895.
---
 cime_config/SystemTests/funitshare.py | 26 ++++++++++++++++++++++++++
 cime_config/config_tests.xml          | 18 ++++++++++++++++++
 cime_config/testlist_allactive.xml    |  9 +++++++++
 3 files changed, 53 insertions(+)
 create mode 100644 cime_config/SystemTests/funitshare.py
 create mode 100644 cime_config/config_tests.xml

diff --git a/cime_config/SystemTests/funitshare.py b/cime_config/SystemTests/funitshare.py
new file mode 100644
index 000000000..7d28f75c8
--- /dev/null
+++ b/cime_config/SystemTests/funitshare.py
@@ -0,0 +1,26 @@
+"""
+Implementation of the share code FUNIT test.
+
+This "system" test runs the share code's Fortran unit tests. We're abusing the system test
+infrastructure to run these, so that a run of the test suite can result in the unit tests
+being run as well.
+
+Grid and compset are irrelevant for this test type.
+"""
+
+import os
+from CIME.SystemTests.funit import FUNIT
+from CIME.XML.standard_module_setup import *
+
+logger = logging.getLogger(__name__)
+
+
+class FUNITSHARE(FUNIT):
+    def __init__(self, case):
+        FUNIT.__init__(self, case)
+
+    def get_test_spec_dir(self):
+        return os.path.join(self._case.get_value("SRCROOT"), "share")
+
+    def get_extra_run_tests_args(self):
+        return '--cmake-args " -DUNITTESTS=ON -DUSE_CIME_MACROS=ON"'
diff --git a/cime_config/config_tests.xml b/cime_config/config_tests.xml
new file mode 100644
index 000000000..4b14b8676
--- /dev/null
+++ b/cime_config/config_tests.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+
+<!--
+This defines various CESM-specific system tests
+-->
+
+<config_test>
+
+  <test NAME="FUNITSHARE">
+    <DESC>Run the share code's Fortran unit tests. Grid and compset (and most case settings) are ignored.</DESC>
+    <INFO_DBUG>1</INFO_DBUG>
+    <STOP_OPTION>ndays</STOP_OPTION>
+    <STOP_N>11</STOP_N>
+    <CHECK_TIMING>FALSE</CHECK_TIMING>
+    <DOUT_S>FALSE</DOUT_S>
+  </test>
+
+</config_test>
diff --git a/cime_config/testlist_allactive.xml b/cime_config/testlist_allactive.xml
index 4c6878a7e..9c7952484 100644
--- a/cime_config/testlist_allactive.xml
+++ b/cime_config/testlist_allactive.xml
@@ -251,4 +251,13 @@
      <option name="comment">Include a short debug test using the atm grid for aoflux calculations rather than the default xgrid.</option>
    </options>
  </test>
+  <test name="FUNITSHARE_P1x1" grid="ne30pg3_t232" compset="B1850C_LTso">
+    <machines>
+      <machine name="derecho" compiler="intel" category="prealpha"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:30:00</option>
+      <option name="comment">This test runs the CESM_share Fortran unit tests. We're abusing the system test infrastructure to run these, so that a run of the test suite results in the unit tests being run as well. These unit tests are run as a GitHub action for each share PR, so this system test is less about catching code problems and more about making sure the unit testing infrastructure continues to work in each CESM tag. Grid and compset are irrelevant here.</option>
+    </options>
+  </test>
 </testlist>

From e9249aecd4a33d3373ace9973ca73571cbf4b954 Mon Sep 17 00:00:00 2001
From: Bill Sacks <sacks@ucar.edu>
Date: Sun, 9 Nov 2025 13:08:06 -0700
Subject: [PATCH 2/2] FUNITSHARE test needs to be mpi-serial to load the
 necessary modules

---
 cime_config/SystemTests/funitshare.py | 7 +++++++
 cime_config/testlist_allactive.xml    | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/cime_config/SystemTests/funitshare.py b/cime_config/SystemTests/funitshare.py
index 7d28f75c8..8f6a8f76c 100644
--- a/cime_config/SystemTests/funitshare.py
+++ b/cime_config/SystemTests/funitshare.py
@@ -19,6 +19,13 @@ class FUNITSHARE(FUNIT):
     def __init__(self, case):
         FUNIT.__init__(self, case)
 
+        # The CMake build for the share unit tests uses the MPISERIAL env var to find the
+        # mpi-serial library. On derecho, MPISERIAL is not set even if the mpi-serial
+        # module is loaded; instead, there is an NCAR_ROOT_MPI_SERIAL variable. Set the
+        # needed MPISERIAL env var for this test.
+        if "NCAR_ROOT_MPI_SERIAL" in os.environ:
+            os.environ["MPISERIAL"] = os.environ["NCAR_ROOT_MPI_SERIAL"]
+
     def get_test_spec_dir(self):
         return os.path.join(self._case.get_value("SRCROOT"), "share")
 
diff --git a/cime_config/testlist_allactive.xml b/cime_config/testlist_allactive.xml
index 9c7952484..95a993f4f 100644
--- a/cime_config/testlist_allactive.xml
+++ b/cime_config/testlist_allactive.xml
@@ -251,13 +251,13 @@
      <option name="comment">Include a short debug test using the atm grid for aoflux calculations rather than the default xgrid.</option>
    </options>
  </test>
-  <test name="FUNITSHARE_P1x1" grid="ne30pg3_t232" compset="B1850C_LTso">
+  <test name="FUNITSHARE_P1x1_Mmpi-serial" grid="ne30pg3_t232" compset="B1850C_LTso">
     <machines>
       <machine name="derecho" compiler="intel" category="prealpha"/>
     </machines>
     <options>
       <option name="wallclock">00:30:00</option>
-      <option name="comment">This test runs the CESM_share Fortran unit tests. We're abusing the system test infrastructure to run these, so that a run of the test suite results in the unit tests being run as well. These unit tests are run as a GitHub action for each share PR, so this system test is less about catching code problems and more about making sure the unit testing infrastructure continues to work in each CESM tag. Grid and compset are irrelevant here.</option>
+      <option name="comment">This test runs the CESM_share Fortran unit tests. We're abusing the system test infrastructure to run these, so that a run of the test suite results in the unit tests being run as well. These unit tests are run as a GitHub action for each share PR, so this system test is less about catching code problems and more about making sure the unit testing infrastructure continues to work in each CESM tag. Grid and compset are irrelevant here. Needs to be mpi-serial in order to load the necessary modules.</option>
     </options>
   </test>
 </testlist>