Fix empty neuron.__version__ when git describe fails in shallow clones

Release dry-runs build wheels from a depth-1 checkout without creating the
release tag. git describe then fails while .git still exists, so GIT_DESCRIBE
stayed empty and neuron.__version__ (nrnversion(5)) was "", breaking ModelDB
CI workdir creation. Fall back to PROJECT_VERSION and assert non-empty
__version__ in wheel tests.

Author: nrnhines

cmake/MacroHelper.cmake

@@ -256,11 +256,21 @@ endfunction()
 function(add_cpp_git_information target scope)
   find_program(GIT git)
   if(EXISTS "${PROJECT_SOURCE_DIR}/.git" AND GIT)
+    # Shallow clones: tags may not be ancestors of HEAD, so describe fails and
+    # GIT_DESCRIBE would stay empty (neuron.__version__ / nrnversion(5)). Fall
+    # back to PROJECT_VERSION so release dry-run and ship wheels match.
     execute_process(
       COMMAND "${GIT}" -C "${PROJECT_SOURCE_DIR}" describe
       OUTPUT_VARIABLE GIT_DESCRIBE
+      RESULT_VARIABLE GIT_DESCRIBE_RESULT
       OUTPUT_STRIP_TRAILING_WHITESPACE ERROR_QUIET)
 
+    if(GIT_DESCRIBE_RESULT OR "${GIT_DESCRIBE}" STREQUAL "")
+      set(GIT_DESCRIBE "${PROJECT_VERSION}")
+      message(
+        STATUS "git describe failed or empty; falling back to PROJECT_VERSION=${PROJECT_VERSION}")
+    endif()
+
     execute_process(
       COMMAND "${GIT}" -C "${PROJECT_SOURCE_DIR}" rev-parse --abbrev-ref HEAD
       OUTPUT_VARIABLE GIT_BRANCH

packaging/python/test_wheels.sh

@@ -256,6 +256,8 @@ $python_exe -m uv pip install -r packaging/python/test_requirements.txt
 $python_exe -m uv pip install --force-reinstall $python_wheel
 $python_exe -m uv pip show neuron || $python_exe -m uv pip show neuron-nightly
 
+# neuron.__version__ is nrnversion(5)/GIT_DESCRIBE; empty breaks ModelDB workdir naming
+$python_exe -c "import neuron; v = neuron.__version__; assert v and str(v).strip(), repr(v)"
 
 # check the existence of coreneuron support
 compile_options="$(nrniv -nobanner -nogui -c 'nrnversion(6)')"