Investigate unexpected licence check failures.

[pp-mo]

I can't any difference between the licence headers of test_grid_definition_template_40.py and test_grid_definition_template_140.py, but the latter is failing.

The header check only runs on files changed in the current commit (or something like).
So we shall see whether this fails on the old file (previously apparently OK) or not ...

[pp-mo]

Weirder and weirder...

In this PR, it still complains about the file "..._140.py".
But that file is not changed, so should not get tested here IIUC.

And still I can detect no difference in the header lines between this and the "..._40.py" one.

[pp-mo]

The latest results do seem to show that there is not anything wrong in the "test_..._140.py" file,
since it does not appear alongside "test_..._20.py" in the list of failing ones shown in the test output.

So far, I am stumped by this. There must be something wrong with how the test is working.
@trexfeathers can you make any sense of what might be happening here ?

[trexfeathers]

The latest results do seem to show that there is not anything wrong in the "test_...140.py" file, since it does not appear alongside "test..._20.py" in the list of failing ones shown in the test output.

So far, I am stumped by this. There must be something wrong with how the test is working. @trexfeathers can you make any sense of what might be happening here ?

I think you're looking in the wrong place. The failure is in test_grid_definition_template_140.py within save_rules/ (not load_convert/). The one in save rules does indeed have the wrong licence header:

iris-grib/iris_grib/tests/unit/save_rules/test_grid_definition_template_140.py

Lines 1 to 5 in 831ea25

	# Copyright iris-grib contributors
	#
	# This file is part of iris-grib and is released under the LGPL license.
	# See COPYING and COPYING.LESSER in the root of the repository for full
	# licensing details.

This got merged unnoticed because #343 was raised before #359, but was merged AFTER it. We have got used to the excellent functionality of GHA, which gives us CI against a simulated merge, whereas Cirrus runs CI on the branch itself. This meant that #343 passed, because the licence header test on #343 was still asserting for the old header.

I assumed that the failures on #371 couldn't possibly be real, since I had not modified the file in question. But the failures were real, they just hadn't been noticed before. I'm probably going to run out of time to raise a fix PR this evening, but I'd be happy to merge one if you raised it.

[pp-mo]

Looking at the wrong file !
There are two files called test_grid_definition_template_140.py,
I have been looking at tests/unit/load_convert,
but the one that matter is in tests/unit/save_rules