Add manage externals to access MMM-physics repo (#2126)

TYPE: enhancement, no impact

KEYWORDS: manage_externals, some physics for tropical suite

SOURCE: internal

DESCRIPTION OF CHANGES:
Add the use of manage_externals tool to access physics in
[MMM-physics](https://github.com/NCAR/MMM-physics) repository. The
physics we access are part of the 'tropical' suite: YSU PBL, revised MM5
surface layer, WSM6 microphysics, and new Tiedtke scheme. It also
accesses GWDO option 1 routine. These modules have been residing in
phys/physics_mmm/ in 4.6. Instead of copied files in this directory, we
now use manage_externals to access these modules from MMM-physics
repository.

Will need to update the tags specified in Externals.cfg before final
release.

LIST OF MODIFIED FILES: 
A       arch/Externals.cfg
M       phys/Makefile
D       phys/physics_mmm/bl_gwdo.F90
D       phys/physics_mmm/bl_ysu.F90
D       phys/physics_mmm/cu_ntiedtke.F90
D       phys/physics_mmm/module_libmassv.F90
D       phys/physics_mmm/mp_radar.F90
D       phys/physics_mmm/mp_wsm6.F90
D       phys/physics_mmm/mp_wsm6_effectRad.F90
D       phys/physics_mmm/sf_sfclayrev.F90
A       tools/manage_externals/

TESTS CONDUCTED: 
1. Successfully compiled the code on Derecho.
2. Are the Jenkins tests all passing?

RELEASE NOTE: Add manage_externals tool to access physics modules in
MMM-physics git repository.

CMakeLists.txt

@@ -320,6 +320,29 @@ if ( ${USE_IPO} )
 endif()
 
 
+
+################################################################################
+##
+## Checkout external repositories using manage_externals
+##
+################################################################################
+message( STATUS "Checking out external repos via manage_externals" )
+set( LOG_FILE      ${CMAKE_CURRENT_BINARY_DIR}/checkout_externals.log )
+execute_process(
+                COMMAND
+                  ${PROJECT_SOURCE_DIR}/tools/manage_externals/checkout_externals --externals ${PROJECT_SOURCE_DIR}/arch/Externals.cfg
+                WORKING_DIRECTORY       ${PROJECT_SOURCE_DIR}
+                RESULT_VARIABLE         MANAGE_EXTERNALS_STATUS
+                OUTPUT_FILE             ${LOG_FILE}
+                ERROR_FILE              ${LOG_FILE}
+                )
+if ( ${MANAGE_EXTERNALS_STATUS} AND NOT ${MANAGE_EXTERNALS_STATUS} EQUAL 0 )
+  message( FATAL_ERROR "Failed to checkout external repos via manage_externals" )
+else()
+  message( STATUS "Finished checking out external repos via manage_externals" )
+endif()
+
+
 ################################################################################
 ##
 ## Create our flags / defines properties and variables to carry our information

arch/Externals.cfg

@@ -0,0 +1,10 @@
+[MMM-physics]
+local_path = ./phys/physics_mmm
+protocol = git
+repo_url = https://github.com/NCAR/MMM-physics.git
+tag = 20240626-MPASv8.2
+
+required = True
+
+[externals_description]
+schema_version = 1.0.0

phys/Makefile

@@ -249,6 +249,7 @@ LIBTARGET    =  physics
 TARGETDIR    =  ./
 
 $(LIBTARGET) :
+	(cd .. && ./tools/manage_externals/checkout_externals --externals ./arch/Externals.cfg)
 	$(MAKE) $(J) non_nmm ; \
 	$(AR) $(ARFLAGS) ../main/$(LIBWRFLIB) $(MODULES) $(OBJS)  \
 		$(FIRE_MODULES) $(DIAGNOSTIC_MODULES_EM) $(PHYSMMM_MODULES)