Update ChangeLog.

Author: nusbaume

doc/ChangeLog

@@ -1,5 +1,94 @@
 ===============================================================
 
+Tag name: cam6_4_127
+Originator(s):  courtneyp, jedwards
+Date: Oct 24, 2025
+One-line Summary: Remove unset diagnostic fields from RRTMGP + update git-fleximod
+Github PR URL: https://github.com/ESCOMP/CAM/pull/1420
+
+Purpose of changes (include the issue number and title text for each relevant GitHub issue):
+  - Remove unset diagnostic variables from RRTMGP: https://github.com/ESCOMP/CAM/issues/1419
+  - Incorrect subtree ./lib/git-fleximod/git-fleximod: https://github.com/ESCOMP/CAM/issues/1421
+
+Describe any changes made to build system: N/A
+
+Describe any changes made to the namelist: N/A
+
+List any changes to the defaults for the boundary datasets: N/A
+
+Describe any substantial timing or memory changes: N/A
+
+Code reviewed by: nusbaume
+
+List all files eliminated:
+
+D       .lib/CODE_OF_CONDUCT.md
+D       .lib/License
+D       .lib/README.md
+D       .lib/doc/Makefile
+D       .lib/doc/conf.py
+D       .lib/doc/index.rst
+D       .lib/doc/make.bat
+D       .lib/escomp_install
+D       .lib/git_fleximod/__init__.py
+D       .lib/git_fleximod/cli.py
+D       .lib/git_fleximod/git_fleximod.py
+D       .lib/git_fleximod/gitinterface.py
+D       .lib/git_fleximod/gitmodules.py
+D       .lib/git_fleximod/lstripreader.py
+D       .lib/git_fleximod/metoflexi.py
+D       .lib/git_fleximod/submodule.py
+D       .lib/git_fleximod/utils.py
+D       .lib/poetry.lock
+D       .lib/pyproject.toml
+D       .lib/tbump.toml
+D       .lib/tests/__init__.py
+D       .lib/tests/conftest.py
+D       .lib/tests/test_a_import.py
+D       .lib/tests/test_b_update.py
+D       .lib/tests/test_c_required.py
+D       .lib/tests/test_d_complex.py
+D       .lib/tests/test_e_complex_update.py
+  - Remove bad copy of git-fleximod
+
+
+List all files added and what they do: N/A
+
+List all existing files that have been modified, and describe the changes:
+
+M       .lib/git-fleximod/.github/workflows/pytest.yaml
+M       .lib/git-fleximod/README.md
+M       .lib/git-fleximod/git_fleximod/cli.py
+M       .lib/git-fleximod/git_fleximod/git_fleximod.py
+M       .lib/git-fleximod/git_fleximod/gitinterface.py
+M       .lib/git-fleximod/git_fleximod/submodule.py
+M       .lib/git-fleximod/pyproject.toml
+M       .lib/git-fleximod/tbump.toml
+M       .lib/git-fleximod/tests/conftest.py
+M       .lib/git-fleximod/tests/test_c_required.py
+  - Update git-fleximod to version 1.0.3
+
+M       src/physics/rrtmgp/radiation.F90
+  - Remove unused diagnostic history fields
+
+If there were any failures reported from running test_driver.sh on any test
+platform, and checkin with these failures has been OK'd by the gatekeeper,
+then copy the lines from the td.*.status files for the failed tests to the
+appropriate machine below.  All failed tests must be justified.
+
+derecho/intel/aux_cam: ALL PASS
+
+derecho/nvhpc/aux_cam: ALL PASS
+
+izumi/nag/aux_cam: ALL PASS
+
+izumi/gnu/aux_cam: ALL PASS
+
+Summarize any changes to answers:  No answers were changed with this PR.
+
+===============================================================
+===============================================================
+
 Tag name: cam6_4_126
 Originator(s):  Walter Hannah, Jack Chen, Peter Lauritzen, Cheryl Craig
 Date: Oct 16, 2025