Lockfiles debug

[pp-mo]

Actually an attempt to dig a bit deeper into the #6096 #6135 problems

[pp-mo]

Results

The env dump in the py3.12 tests went like this, in part ...

2024-09-04T16:44:11.9294931Z nox > python -m pip install --no-deps --editable .
2024-09-04T16:44:18.3399127Z nox > echo '"NOX TEST ENV DUMP == START "'
2024-09-04T16:44:18.3409259Z "NOX TEST ENV DUMP == START "
2024-09-04T16:44:18.3413493Z nox > env 
2024-09-04T16:44:18.3423399Z SYSTEMROOT=
2024-09-04T16:44:18.3424153Z SELENIUM_JAR_PATH=/usr/share/java/selenium-server.jar
2024-09-04T16:44:18.3424913Z CONDA=/home/runner/miniconda3
2024-09-04T16:44:18.3425544Z GITHUB_WORKSPACE=/home/runner/work/iris/iris
2024-09-04T16:44:18.3426381Z JAVA_HOME_11_X64=/usr/lib/jvm/temurin-11-jdk-amd64
2024-09-04T16:44:18.3427105Z CONDA_EXE=/home/runner/miniconda3/bin/conda
2024-09-04T16:44:18.3427693Z _CE_M=
2024-09-04T16:44:18.3428105Z ENV_NAME=ci-tests
  . . .
2024-09-04T16:44:18.3490069Z PROJ_DATA=/home/runner/miniconda3/envs/ci-tests/share/proj
 . . .

2024-09-04T16:44:18.3522405Z PROJ_NETWORK=ON
 . . .
2024-09-04T16:44:18.3523626Z NOX_CURRENT_SESSION=tests
2024-09-04T16:44:18.3524201Z TMPDIR=/home/runner/work/iris/iris/.nox/tests/tmp
2024-09-04T16:44:18.3524969Z NPY_DISABLE_CPU_FEATURES=AVX512F,AVX512CD,AVX512_SKX
2024-09-04T16:44:18.3525782Z nox > echo '".. == END NOX TEST ENV DUMP."'
2024-09-04T16:44:18.3526703Z nox > pytest -n auto --cov=lib/iris --cov-report=xml lib/iris/tests
2024-09-04T16:44:18.3527501Z ".. == END NOX TEST ENV DUMP."

Suspected Relevance

So, I have a strong suspicion that the PROJ_DATA=/home/runner/miniconda3/envs/ci-tests/share/proj here
is the key problem.

It does seem from the error messages that this key variable is not re-set to the correct path for the installed test environment, as it should have been. E.G. this message from the #6096 tests :

____________________ Test_GeogCS_mutation.test_datum_change ____________________
[gw1] linux -- Python 3.12.5 /home/runner/work/iris/iris/.nox/tests/bin/python3.12

self = <iris.tests.test_coordsystem.Test_GeogCS_mutation testMethod=test_datum_change>

    def test_datum_change(self):
        # Semi-major axis changes
        # All internal ellipoid values set to None
        # CRS changes
        cs = GeogCS(6543210, 6500000)
>       _ = cs.as_cartopy_crs()

lib/iris/tests/test_coordsystem.py:302: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
lib/iris/coord_systems.py:319: in as_cartopy_crs
    return self._crs
.nox/tests/lib/python3.12/functools.py:993: in __get__
    val = self.func(instance)
lib/iris/coord_systems.py:363: in _crs
    return ccrs.Geodetic(self._globe)
.nox/tests/lib/python3.12/site-packages/cartopy/crs.py:584: in __init__
    super().__init__(proj4_params, globe)
.nox/tests/lib/python3.12/site-packages/cartopy/crs.py:201: in __init__
    super().__init__(self.proj4_init)
.nox/tests/lib/python3.12/site-packages/pyproj/crs/crs.py:348: in __init__
    self._local.crs = _CRS(self.srs)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

>   ???
E   pyproj.exceptions.CRSError: Invalid projection: +proj=lonlat +a=6543210.0 +b=6500000.0 +no_defs +type=crs: (Internal Proj Error: proj_create: /home/runner/miniconda3/envs/ci-tests/share/proj/proj.db contains DATABASE.LAYOUT.VERSION.MINOR = 2 whereas a number >= 3 is expected. It comes from another PROJ installation.)

pyproj/_crs.pyx:2378: CRSError

Trial to replicate

I have now replicated this myself locally, by setting the path into an older conda env. E.G.

$ conda activate /opt/scitools/conda/deployments/default-2024_02_20
$ pytest ./lib/iris/tests/test_coordsystem.py      
$ pytest ./lib/iris/tests/test_coordsystem.py::Test_Datums
=================================================================================== test session starts ===================================================================================
platform linux -- Python 3.11.7, pytest-8.0.0, pluggy-1.4.0
rootdir: /net/home/h05/itpp/git/iris/iris_main
configfile: pyproject.toml
plugins: anyio-4.2.0, xdist-3.5.0
collected 2 items                                                                                                                                                                         

lib/iris/tests/test_coordsystem.py ..                                                                                                                                               [100%]

================================================================================== slowest 25 durations ===================================================================================

(6 durations < 0.005s hidden.  Use -vv to show these durations.)
==================================================================================== 2 passed in 2.50s ====================================================================================
$ set | grep PROJ
PROJ_DATA=/opt/scitools/conda/deployments/default-2024_02_20/share/proj
PROJ_NETWORK=ON
$
$ conda deactivate
$ conda activate /opt/scitools/conda/deployments/default-2024_09_02/
$ pytest ./lib/iris/tests/test_coordsystem.py::Test_Datums
  . . .
==================================================================================== 2 passed in 3.41s ====================================================================================

$ export PROJ_DATA=/opt/scitools/conda/deployments/default-2024_02_20/share/proj
$ pytest ./lib/iris/tests/test_coordsystem.py::Test_Datums
 . . .
======================================================================================== FAILURES =========================================================================================
______________________________________________________________________________ Test_Datums.test_default_none ______________________________________________________________________________

self = <iris.tests.test_coordsystem.Test_Datums testMethod=test_default_none>

    def test_default_none(self):
        cs = GeogCS(6543210, 6500000)  # Arbitrary radii
>       cartopy_crs = cs.as_cartopy_crs()

lib/iris/tests/test_coordsystem.py:524: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
lib/iris/coord_systems.py:319: in as_cartopy_crs
    return self._crs
/opt/scitools/conda/deployments/default-2024_09_02/lib/python3.12/functools.py:993: in __get__
    val = self.func(instance)
lib/iris/coord_systems.py:363: in _crs
    return ccrs.Geodetic(self._globe)
/opt/scitools/conda/deployments/default-2024_09_02/lib/python3.12/site-packages/cartopy/crs.py:584: in __init__
    super().__init__(proj4_params, globe)
/opt/scitools/conda/deployments/default-2024_09_02/lib/python3.12/site-packages/cartopy/crs.py:201: in __init__
    super().__init__(self.proj4_init)
/opt/scitools/conda/deployments/default-2024_09_02/lib/python3.12/site-packages/pyproj/crs/crs.py:348: in __init__
    self._local.crs = _CRS(self.srs)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

>   ???
E   pyproj.exceptions.CRSError: Invalid projection: +proj=lonlat +a=6543210.0 +b=6500000.0 +no_defs +type=crs: (Internal Proj Error: proj_create: /opt/scitools/conda/deployments/default-2024_02_20/share/proj/proj.db contains DATABASE.LAYOUT.VERSION.MINOR = 2 whereas a number >= 3 is expected. It comes from another PROJ installation.)

pyproj/_crs.pyx:2378: CRSError

 . . .
================================================================================= short test summary info =================================================================================
FAILED lib/iris/tests/test_coordsystem.py::Test_Datums::test_default_none - pyproj.exceptions.CRSError: Invalid projection: +proj=lonlat +a=6543210.0 +b=6500000.0 +no_defs +type=crs: (Internal Proj Error: proj_create: /opt/scitools/conda/deployments/default-...
========================================================================= 1 failed, 1 passed, 1 warning in 2.69s ==========================================================================

What it means

From further experiment, activating a conda env with proj/pyproj in it does always set PROJ_DATA, even in the latest versions.
So, I think this must point to a problem or subtlety in nox use of conda - since it seems that the activation of the controlled test environment is not complete -- i.e. somehow it has missed setting PROJ_DATA to the 'correct' value when invoking the test environment.
Perhaps nox has some tricky special behaviour when it is activating the test environment : Something like, if it re-asserts env settings from the 'host' environment afterward, or the settings derived from activation scripts are somehow "fixed" so they can't over-write an existing one.

Certainly, if PROJ_DATA is set like as above, and then the new env is activated with "conda activate", then PROJ_DATA is changed by that as you would expect, and the above error does not occur :

$ export PROJ_DATA=/opt/scitools/conda/deployments/default-2024_02_20/share/proj
$ conda activate /opt/scitools/conda/deployments/default-2024_09_02/
$ set | grep PROJ
PROJ_DATA=/opt/scitools/conda/deployments/default-2024_09_02/share/proj
PROJ_NETWORK=ON
_CONDA_SET_PROJ_DATA=/opt/scitools/conda/deployments/default-2024_02_20/share/proj
$ pytest ./lib/iris/tests/test_coordsystem.py::Test_Datums
  . . .  === 2 passed in 3.64s ====
$ conda deactivate
$ set | grep PROJ
PROJ_DATA=/opt/scitools/conda/deployments/default-2024_02_20/share/proj

• so, this is not a problem with conda activate/deactivate : they get it right.
  I'm guessing this may something tricky in nox

[github-actions]

⏱️ Performance Benchmark Report: f04064e

Performance shifts

| Change   | Before [1a9bdaa5]    | After [f04064e7]    |   Ratio | Benchmark (Parameter)                                      |
|----------|----------------------|---------------------|---------|------------------------------------------------------------|
| +        | 370±2ms              | 548±3ms             |    1.48 | load.StructuredFF.time_structured_load((2, 2, 1000), True) |

Full benchmark results

Benchmarks that have stayed the same:

| Change   | Before [1a9bdaa5]    | After [f04064e7]    | Ratio   | Benchmark (Parameter)                                                                       |
|----------|----------------------|---------------------|---------|---------------------------------------------------------------------------------------------|
|          | 53.9±0.9ms           | 59.0±0.7ms          | 1.10    | aggregate_collapse.Aggregation.time_aggregated_by_COUNT(False)                              |
|          | 54.3±1ms             | 59.5±0.8ms          | 1.10    | aggregate_collapse.Aggregation.time_aggregated_by_COUNT(True)                               |
|          | 191±2ms              | 212±3ms             | 1.11    | aggregate_collapse.Aggregation.time_aggregated_by_FAST_PERCENTILE(False)                    |
|          | 192±2ms              | 212±2ms             | 1.11    | aggregate_collapse.Aggregation.time_aggregated_by_FAST_PERCENTILE(True)                     |
|          | 37.0±0.8ms           | 38.2±0.4ms          | 1.03    | aggregate_collapse.Aggregation.time_aggregated_by_GMEAN(False)                              |
|          | 37.7±0.9ms           | 39.4±0.7ms          | 1.04    | aggregate_collapse.Aggregation.time_aggregated_by_GMEAN(True)                               |
|          | 37.2±0.7ms           | 38.5±0.6ms          | 1.03    | aggregate_collapse.Aggregation.time_aggregated_by_HMEAN(False)                              |
|          | 37.8±0.6ms           | 38.9±0.9ms          | 1.03    | aggregate_collapse.Aggregation.time_aggregated_by_HMEAN(True)                               |
|          | 46.9±0.8ms           | 50.7±0.6ms          | 1.08    | aggregate_collapse.Aggregation.time_aggregated_by_MAX(False)                                |
|          | 47.7±0.7ms           | 52.0±0.9ms          | 1.09    | aggregate_collapse.Aggregation.time_aggregated_by_MAX(True)                                 |
|          | 121±1ms              | 138±2ms             | 1.14    | aggregate_collapse.Aggregation.time_aggregated_by_MAX_RUN(False)                            |
|          | 123±1ms              | 137±2ms             | 1.11    | aggregate_collapse.Aggregation.time_aggregated_by_MAX_RUN(True)                             |
|          | 51.4±0.6ms           | 55.4±1ms            | 1.08    | aggregate_collapse.Aggregation.time_aggregated_by_MEAN(False)                               |
|          | 52.2±0.9ms           | 56.0±0.6ms          | 1.07    | aggregate_collapse.Aggregation.time_aggregated_by_MEAN(True)                                |
|          | 36.7±0.7ms           | 38.4±0.6ms          | 1.05    | aggregate_collapse.Aggregation.time_aggregated_by_MEDIAN(False)                             |
|          | 37.6±0.4ms           | 38.8±0.2ms          | 1.03    | aggregate_collapse.Aggregation.time_aggregated_by_MEDIAN(True)                              |
|          | 46.6±0.4ms           | 50.3±0.6ms          | 1.08    | aggregate_collapse.Aggregation.time_aggregated_by_MIN(False)                                |
|          | 48.0±0.7ms           | 51.4±0.5ms          | 1.07    | aggregate_collapse.Aggregation.time_aggregated_by_MIN(True)                                 |
|          | 1.32±0.02s           | 1.35±0.02s          | 1.02    | aggregate_collapse.Aggregation.time_aggregated_by_PEAK(False)                               |
|          | 1.32±0.02s           | 1.34±0.01s          | 1.02    | aggregate_collapse.Aggregation.time_aggregated_by_PEAK(True)                                |
|          | 684±10ms             | 689±7ms             | 1.01    | aggregate_collapse.Aggregation.time_aggregated_by_PERCENTILE(False)                         |
|          | 681±20ms             | 690±20ms            | 1.01    | aggregate_collapse.Aggregation.time_aggregated_by_PERCENTILE(True)                          |
|          | 35.2±0.4ms           | 37.0±0.3ms          | 1.05    | aggregate_collapse.Aggregation.time_aggregated_by_PROPORTION(False)                         |
|          | 35.9±0.5ms           | 37.5±0.4ms          | 1.04    | aggregate_collapse.Aggregation.time_aggregated_by_PROPORTION(True)                          |
|          | 62.2±0.9ms           | 68.4±0.6ms          | 1.10    | aggregate_collapse.Aggregation.time_aggregated_by_RMS(False)                                |
|          | 62.6±0.7ms           | 68.9±0.5ms          | 1.10    | aggregate_collapse.Aggregation.time_aggregated_by_RMS(True)                                 |
|          | 65.9±1ms             | 70.0±0.6ms          | 1.06    | aggregate_collapse.Aggregation.time_aggregated_by_STD_DEV(False)                            |
|          | 67.1±0.5ms           | 71.5±0.5ms          | 1.07    | aggregate_collapse.Aggregation.time_aggregated_by_STD_DEV(True)                             |
|          | 61.7±0.7ms           | 65.6±0.9ms          | 1.06    | aggregate_collapse.Aggregation.time_aggregated_by_VARIANCE(False)                           |
|          | 62.3±0.9ms           | 66.1±0.6ms          | 1.06    | aggregate_collapse.Aggregation.time_aggregated_by_VARIANCE(True)                            |
|          | 20.0±0.5ms           | 21.1±0.7ms          | 1.06    | aggregate_collapse.Aggregation.time_collapsed_by_COUNT(False)                               |
|          | 23.5±0.4ms           | 24.9±0.6ms          | 1.06    | aggregate_collapse.Aggregation.time_collapsed_by_COUNT(True)                                |
|          | 130±1ms              | 142±2ms             | 1.09    | aggregate_collapse.Aggregation.time_collapsed_by_FAST_PERCENTILE(False)                     |
|          | 145±1ms              | 157±2ms             | 1.08    | aggregate_collapse.Aggregation.time_collapsed_by_FAST_PERCENTILE(True)                      |
|          | 18.3±0.4ms           | 18.6±0.4ms          | 1.02    | aggregate_collapse.Aggregation.time_collapsed_by_GMEAN(False)                               |
|          | 22.1±0.4ms           | 23.1±0.5ms          | 1.05    | aggregate_collapse.Aggregation.time_collapsed_by_GMEAN(True)                                |
|          | 18.1±0.6ms           | 18.5±0.8ms          | 1.02    | aggregate_collapse.Aggregation.time_collapsed_by_HMEAN(False)                               |
|          | 22.1±0.4ms           | 22.9±0.9ms          | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_HMEAN(True)                                |
|          | 18.8±0.4ms           | 19.2±0.6ms          | 1.02    | aggregate_collapse.Aggregation.time_collapsed_by_MAX(False)                                 |
|          | 22.8±0.6ms           | 23.6±0.7ms          | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_MAX(True)                                  |
|          | 34.5±1ms             | 37.3±1ms            | 1.08    | aggregate_collapse.Aggregation.time_collapsed_by_MAX_RUN(False)                             |
|          | 38.1±0.6ms           | 41.2±0.6ms          | 1.08    | aggregate_collapse.Aggregation.time_collapsed_by_MAX_RUN(True)                              |
|          | 19.2±0.3ms           | 20.3±0.7ms          | 1.06    | aggregate_collapse.Aggregation.time_collapsed_by_MEAN(False)                                |
|          | 22.8±0.4ms           | 24.4±0.3ms          | 1.07    | aggregate_collapse.Aggregation.time_collapsed_by_MEAN(True)                                 |
|          | 18.8±0.2ms           | 19.1±0.5ms          | 1.02    | aggregate_collapse.Aggregation.time_collapsed_by_MEDIAN(False)                              |
|          | 22.5±0.4ms           | 23.7±0.7ms          | 1.05    | aggregate_collapse.Aggregation.time_collapsed_by_MEDIAN(True)                               |
|          | 18.7±0.5ms           | 19.3±1ms            | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_MIN(False)                                 |
|          | 22.3±0.2ms           | 23.6±0.9ms          | 1.06    | aggregate_collapse.Aggregation.time_collapsed_by_MIN(True)                                  |
|          | 554±5ms              | 577±3ms             | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_PEAK(False)                                |
|          | 557±8ms              | 582±6ms             | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_PEAK(True)                                 |
|          | 151±1ms              | 160±2ms             | 1.06    | aggregate_collapse.Aggregation.time_collapsed_by_PERCENTILE(False)                          |
|          | 168±2ms              | 180±1ms             | 1.07    | aggregate_collapse.Aggregation.time_collapsed_by_PERCENTILE(True)                           |
|          | 17.9±0.2ms           | 17.9±0.8ms          | 1.00    | aggregate_collapse.Aggregation.time_collapsed_by_PROPORTION(False)                          |
|          | 21.7±0.2ms           | 22.4±0.9ms          | 1.03    | aggregate_collapse.Aggregation.time_collapsed_by_PROPORTION(True)                           |
|          | 21.2±0.2ms           | 21.9±1ms            | 1.03    | aggregate_collapse.Aggregation.time_collapsed_by_RMS(False)                                 |
|          | 24.9±0.2ms           | 25.9±1ms            | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_RMS(True)                                  |
|          | 21.2±0.3ms           | 21.7±1ms            | 1.02    | aggregate_collapse.Aggregation.time_collapsed_by_STD_DEV(False)                             |
|          | 25.0±0.6ms           | 25.9±0.6ms          | 1.04    | aggregate_collapse.Aggregation.time_collapsed_by_STD_DEV(True)                              |
|          | 20.6±0.3ms           | 21.1±0.9ms          | 1.02    | aggregate_collapse.Aggregation.time_collapsed_by_VARIANCE(False)                            |
|          | 24.4±0.3ms           | 25.5±0.6ms          | 1.05    | aggregate_collapse.Aggregation.time_collapsed_by_VARIANCE(True)                             |
|          | 83.6±0.7ms           | 93.0±0.6ms          | 1.11    | aggregate_collapse.WeightedAggregation.time_w_aggregated_by_MEAN(False)                     |
|          | 84.2±1ms             | 93.3±1ms            | 1.11    | aggregate_collapse.WeightedAggregation.time_w_aggregated_by_MEAN(True)                      |
|          | 95.4±1ms             | 107±1ms             | 1.12    | aggregate_collapse.WeightedAggregation.time_w_aggregated_by_RMS(False)                      |
|          | 96.3±0.5ms           | 107±0.8ms           | 1.11    | aggregate_collapse.WeightedAggregation.time_w_aggregated_by_RMS(True)                       |
|          | 58.8±0.8ms           | 63.8±0.6ms          | 1.09    | aggregate_collapse.WeightedAggregation.time_w_aggregated_by_SUM(False)                      |
|          | 59.2±0.6ms           | 64.3±0.8ms          | 1.09    | aggregate_collapse.WeightedAggregation.time_w_aggregated_by_SUM(True)                       |
|          | 29.3±0.3ms           | 30.3±0.5ms          | 1.03    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_MEAN(False)                      |
|          | 32.9±0.4ms           | 34.5±0.7ms          | 1.05    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_MEAN(True)                       |
|          | 30.9±0.6ms           | 32.8±0.7ms          | 1.06    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_RMS(False)                       |
|          | 34.7±0.7ms           | 37.0±0.4ms          | 1.06    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_RMS(True)                        |
|          | 26.0±0.5ms           | 25.8±0.5ms          | 1.00    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_SUM(False)                       |
|          | 29.5±0.5ms           | 30.2±0.4ms          | 1.03    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_SUM(True)                        |
|          | 327±3ms              | 335±3ms             | 1.03    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_WPERCENTILE(False)               |
|          | 347±2ms              | 356±3ms             | 1.03    | aggregate_collapse.WeightedAggregation.time_w_collapsed_by_WPERCENTILE(True)                |
|          | 1.11±0.01ms          | 1.13±0.01ms         | 1.02    | cube.CubeCreation.time_create(False, 'construct')                                           |
|          | 396±4μs              | 395±7μs             | 1.00    | cube.CubeCreation.time_create(False, 'instantiate')                                         |
|          | 951±10μs             | 968±20μs            | 1.02    | cube.CubeCreation.time_create(True, 'construct')                                            |
|          | 577±6μs              | 583±9μs             | 1.01    | cube.CubeCreation.time_create(True, 'instantiate')                                          |
|          | 224±2ms              | 238±5ms             | 1.07    | cube.CubeEquality.time_equality(False, False, 'all_equal')                                  |
|          | 113±0.9ms            | 124±2ms             | 1.10    | cube.CubeEquality.time_equality(False, False, 'coord_inequality')                           |
|          | 234±3ms              | 251±4ms             | 1.07    | cube.CubeEquality.time_equality(False, False, 'data_inequality')                            |
|          | 16.4±0.2μs           | 16.8±0.4μs          | 1.02    | cube.CubeEquality.time_equality(False, False, 'metadata_inequality')                        |
|          | 310±2ms              | 331±3ms             | 1.07    | cube.CubeEquality.time_equality(False, True, 'all_equal')                                   |
|          | 201±2ms              | 220±3ms             | 1.10    | cube.CubeEquality.time_equality(False, True, 'coord_inequality')                            |
|          | 315±3ms              | 340±3ms             | 1.08    | cube.CubeEquality.time_equality(False, True, 'data_inequality')                             |
|          | 16.7±0.2μs           | 17.1±0.1μs          | 1.02    | cube.CubeEquality.time_equality(False, True, 'metadata_inequality')                         |
|          | 225±3ms              | 237±3ms             | 1.05    | cube.CubeEquality.time_equality(True, False, 'all_equal')                                   |
|          | 114±1ms              | 123±1ms             | 1.08    | cube.CubeEquality.time_equality(True, False, 'coord_inequality')                            |
|          | 235±3ms              | 247±3ms             | 1.05    | cube.CubeEquality.time_equality(True, False, 'data_inequality')                             |
|          | 52.9±0.6μs           | 53.8±0.6μs          | 1.02    | cube.CubeEquality.time_equality(True, False, 'metadata_inequality')                         |
|          | 310±3ms              | 331±6ms             | 1.07    | cube.CubeEquality.time_equality(True, True, 'all_equal')                                    |
|          | 201±2ms              | 219±4ms             | 1.09    | cube.CubeEquality.time_equality(True, True, 'coord_inequality')                             |
|          | 319±4ms              | 342±5ms             | 1.07    | cube.CubeEquality.time_equality(True, True, 'data_inequality')                              |
|          | 54.5±0.5μs           | 55.7±1μs            | 1.02    | cube.CubeEquality.time_equality(True, True, 'metadata_inequality')                          |
|          | 784±4μs              | 777±10μs            | 0.99    | import_iris.Iris.time__concatenate                                                          |
|          | 180±2μs              | 180±2μs             | 1.00    | import_iris.Iris.time__constraints                                                          |
|          | 111±1μs              | 110±0.6μs           | 0.99    | import_iris.Iris.time__data_manager                                                         |
|          | 94.5±1μs             | 93.8±0.6μs          | 0.99    | import_iris.Iris.time__deprecation                                                          |
|          | 138±1μs              | 138±2μs             | 1.00    | import_iris.Iris.time__lazy_data                                                            |
|          | 899±5μs              | 893±10μs            | 0.99    | import_iris.Iris.time__merge                                                                |
|          | 77.4±0.6μs           | 77.2±0.4μs          | 1.00    | import_iris.Iris.time__representation                                                       |
|          | 483±6μs              | 484±10μs            | 1.00    | import_iris.Iris.time_analysis                                                              |
|          | 143±2μs              | 140±2μs             | 0.98    | import_iris.Iris.time_analysis__area_weighted                                               |
|          | 110±2μs              | 111±0.9μs           | 1.00    | import_iris.Iris.time_analysis__grid_angles                                                 |
|          | 247±3μs              | 241±2μs             | 0.98    | import_iris.Iris.time_analysis__interpolation                                               |
|          | 192±4μs              | 188±2μs             | 0.98    | import_iris.Iris.time_analysis__regrid                                                      |
|          | 113±1μs              | 113±1μs             | 1.00    | import_iris.Iris.time_analysis__scipy_interpolate                                           |
|          | 139±2μs              | 140±2μs             | 1.00    | import_iris.Iris.time_analysis_calculus                                                     |
|          | 327±5μs              | 331±4μs             | 1.01    | import_iris.Iris.time_analysis_cartography                                                  |
|          | 94.9±0.7μs           | 94.5±0.5μs          | 1.00    | import_iris.Iris.time_analysis_geomerty                                                     |
|          | 224±7μs              | 217±2μs             | 0.96    | import_iris.Iris.time_analysis_maths                                                        |
|          | 98.2±0.5μs           | 97.0±0.9μs          | 0.99    | import_iris.Iris.time_analysis_stats                                                        |
|          | 176±2μs              | 174±2μs             | 0.99    | import_iris.Iris.time_analysis_trajectory                                                   |
|          | 312±7μs              | 303±3μs             | 0.97    | import_iris.Iris.time_aux_factory                                                           |
|          | 84.7±0.9μs           | 84.0±0.4μs          | 0.99    | import_iris.Iris.time_common                                                                |
|          | 165±2μs              | 162±1μs             | 0.98    | import_iris.Iris.time_common_lenient                                                        |
|          | 1.34±0.01ms          | 1.32±0.01ms         | 0.98    | import_iris.Iris.time_common_metadata                                                       |
|          | 133±0.8μs            | 132±1μs             | 1.00    | import_iris.Iris.time_common_mixin                                                          |
|          | 1.18±0.01ms          | 1.19±0.02ms         | 1.01    | import_iris.Iris.time_common_resolve                                                        |
|          | 198±1μs              | 201±1μs             | 1.01    | import_iris.Iris.time_config                                                                |
|          | 125±2μs              | 125±1μs             | 1.00    | import_iris.Iris.time_coord_categorisation                                                  |
|          | 362±4μs              | 368±3μs             | 1.02    | import_iris.Iris.time_coord_systems                                                         |
|          | 750±8μs              | 753±4μs             | 1.00    | import_iris.Iris.time_coords                                                                |
|          | 666±10μs             | 672±10μs            | 1.01    | import_iris.Iris.time_cube                                                                  |
|          | 226±4μs              | 222±2μs             | 0.98    | import_iris.Iris.time_exceptions                                                            |
|          | 78.5±0.4μs           | 76.8±0.5μs          | 0.98    | import_iris.Iris.time_experimental                                                          |
|          | 186±2μs              | 186±2μs             | 1.00    | import_iris.Iris.time_fileformats                                                           |
|          | 250±1μs              | 253±5μs             | 1.01    | import_iris.Iris.time_fileformats__ff                                                       |
|          | 2.68±0.02ms          | 2.71±0.05ms         | 1.01    | import_iris.Iris.time_fileformats__ff_cross_references                                      |
|          | 80.0±0.3μs           | 79.9±0.7μs          | 1.00    | import_iris.Iris.time_fileformats__pp_lbproc_pairs                                          |
|          | 117±0.7μs            | 115±0.8μs           | 0.98    | import_iris.Iris.time_fileformats_abf                                                       |
|          | 410±4μs              | 408±5μs             | 1.00    | import_iris.Iris.time_fileformats_cf                                                        |
|          | 5.41±0.06ms          | 5.31±0.07ms         | 0.98    | import_iris.Iris.time_fileformats_dot                                                       |
|          | 75.2±0.6μs           | 74.3±0.8μs          | 0.99    | import_iris.Iris.time_fileformats_name                                                      |
|          | 262±6μs              | 257±4μs             | 0.98    | import_iris.Iris.time_fileformats_name_loaders                                              |
|          | 119±2μs              | 119±1μs             | 1.00    | import_iris.Iris.time_fileformats_netcdf                                                    |
|          | 125±1μs              | 123±1μs             | 0.98    | import_iris.Iris.time_fileformats_nimrod                                                    |
|          | 215±4μs              | 215±3μs             | 1.00    | import_iris.Iris.time_fileformats_nimrod_load_rules                                         |
|          | 780±3μs              | 780±7μs             | 1.00    | import_iris.Iris.time_fileformats_pp                                                        |
|          | 185±3μs              | 183±1μs             | 0.99    | import_iris.Iris.time_fileformats_pp_load_rules                                             |
|          | 135±1μs              | 135±0.7μs           | 1.01    | import_iris.Iris.time_fileformats_pp_save_rules                                             |
|          | 516±5μs              | 524±7μs             | 1.02    | import_iris.Iris.time_fileformats_rules                                                     |
|          | 220±2μs              | 219±2μs             | 1.00    | import_iris.Iris.time_fileformats_structured_array_identification                           |
|          | 84.2±0.3μs           | 82.8±0.4μs          | 0.98    | import_iris.Iris.time_fileformats_um                                                        |
|          | 162±3μs              | 161±2μs             | 0.99    | import_iris.Iris.time_fileformats_um__fast_load                                             |
|          | 139±0.8μs            | 138±0.9μs           | 0.99    | import_iris.Iris.time_fileformats_um__fast_load_structured_fields                           |
|          | 76.1±0.5μs           | 75.1±0.3μs          | 0.99    | import_iris.Iris.time_fileformats_um__ff_replacement                                        |
|          | 81.9±1μs             | 81.9±0.7μs          | 1.00    | import_iris.Iris.time_fileformats_um__optimal_array_structuring                             |
|          | 983±4μs              | 981±5μs             | 1.00    | import_iris.Iris.time_fileformats_um_cf_map                                                 |
|          | 137±1μs              | 137±0.9μs           | 1.00    | import_iris.Iris.time_io                                                                    |
|          | 173±1μs              | 173±3μs             | 1.00    | import_iris.Iris.time_io_format_picker                                                      |
|          | 230±2μs              | 232±5μs             | 1.01    | import_iris.Iris.time_iris                                                                  |
|          | 128±1μs              | 127±0.6μs           | 0.99    | import_iris.Iris.time_iterate                                                               |
|          | 8.44±0.09ms          | 8.38±0.09ms         | 0.99    | import_iris.Iris.time_palette                                                               |
|          | 2.21±0.04ms          | 2.24±0.03ms         | 1.02    | import_iris.Iris.time_plot                                                                  |
|          | 105±0.5μs            | 104±4μs             | 0.99    | import_iris.Iris.time_quickplot                                                             |
|          | 2.18±0.03ms          | 2.20±0.04ms         | 1.01    | import_iris.Iris.time_std_names                                                             |
|          | 1.78±0.03ms          | 1.83±0.03ms         | 1.03    | import_iris.Iris.time_symbols                                                               |
|          | 12.8±0.5ms           | 12.7±0.5ms          | 0.99    | import_iris.Iris.time_tests                                                                 |
|          | 261±3μs              | 255±2μs             | 0.98    | import_iris.Iris.time_third_party_cartopy                                                   |
|          | 4.79±0.03ms          | 4.82±0.04ms         | 1.01    | import_iris.Iris.time_third_party_cf_units                                                  |
|          | 120±0.7μs            | 118±0.8μs           | 0.98    | import_iris.Iris.time_third_party_cftime                                                    |
|          | 2.79±0.01ms          | 2.85±0.02ms         | 1.02    | import_iris.Iris.time_third_party_matplotlib                                                |
|          | 1.07±0ms             | 1.07±0.01ms         | 1.00    | import_iris.Iris.time_third_party_numpy                                                     |
|          | 174±1μs              | 171±1μs             | 0.98    | import_iris.Iris.time_third_party_scipy                                                     |
|          | 101±0.6μs            | 100±0.9μs           | 0.99    | import_iris.Iris.time_time                                                                  |
|          | 325±3μs              | 319±3μs             | 0.98    | import_iris.Iris.time_util                                                                  |
|          | 73.3±2μs             | 73.6±0.9μs          | 1.00    | iterate.IZip.time_izip                                                                      |
|          | 8.17±0.09ms          | 9.15±0.09ms         | 1.12    | load.LoadAndRealise.time_load((1280, 960, 5), False, 'FF')                                  |
|          | 24.6±0.2ms           | 23.9±0.4ms          | 0.97    | load.LoadAndRealise.time_load((1280, 960, 5), False, 'NetCDF')                              |
|          | 8.90±0.05ms          | 9.84±0.08ms         | 1.11    | load.LoadAndRealise.time_load((1280, 960, 5), False, 'PP')                                  |
|          | 8.11±0.08ms          | 9.10±0.1ms          | 1.12    | load.LoadAndRealise.time_load((1280, 960, 5), True, 'FF')                                   |
|          | 21.5±0.4ms           | 21.8±0.3ms          | 1.02    | load.LoadAndRealise.time_load((1280, 960, 5), True, 'NetCDF')                               |
|          | 8.86±0.04ms          | 9.91±0.04ms         | 1.12    | load.LoadAndRealise.time_load((1280, 960, 5), True, 'PP')                                   |
|          | 1.37±0.01s           | 1.56±0.01s          | 1.14    | load.LoadAndRealise.time_load((2, 2, 1000), False, 'FF')                                    |
|          | 21.2±0.3ms           | 22.0±0.3ms          | 1.04    | load.LoadAndRealise.time_load((2, 2, 1000), False, 'NetCDF')                                |
|          | 1.52±0.01s           | 1.74±0.02s          | 1.15    | load.LoadAndRealise.time_load((2, 2, 1000), False, 'PP')                                    |
|          | 1.37±0.01s           | 1.56±0.02s          | 1.14    | load.LoadAndRealise.time_load((2, 2, 1000), True, 'FF')                                     |
|          | 21.4±0.4ms           | 22.0±0.4ms          | 1.03    | load.LoadAndRealise.time_load((2, 2, 1000), True, 'NetCDF')                                 |
|          | 1.52±0.01s           | 1.73±0.02s          | 1.14    | load.LoadAndRealise.time_load((2, 2, 1000), True, 'PP')                                     |
|          | 4.01±0.07ms          | 4.34±0.04ms         | 1.08    | load.LoadAndRealise.time_load((50, 50, 2), False, 'FF')                                     |
|          | 20.4±0.2ms           | 20.3±0.3ms          | 0.99    | load.LoadAndRealise.time_load((50, 50, 2), False, 'NetCDF')                                 |
|          | 4.26±0.08ms          | 4.62±0.04ms         | 1.08    | load.LoadAndRealise.time_load((50, 50, 2), False, 'PP')                                     |
|          | 3.95±0.04ms          | 4.31±0.03ms         | 1.09    | load.LoadAndRealise.time_load((50, 50, 2), True, 'FF')                                      |
|          | 20.5±0.4ms           | 20.3±0.2ms          | 0.99    | load.LoadAndRealise.time_load((50, 50, 2), True, 'NetCDF')                                  |
|          | 4.27±0.02ms          | 4.62±0.02ms         | 1.08    | load.LoadAndRealise.time_load((50, 50, 2), True, 'PP')                                      |
|          | 33.3±3ms             | 34.3±3ms            | 1.03    | load.LoadAndRealise.time_realise((1280, 960, 5), False, 'FF')                               |
|          | 19.4±0.5ms           | 19.9±0.4ms          | 1.02    | load.LoadAndRealise.time_realise((1280, 960, 5), False, 'NetCDF')                           |
|          | 13.5±3ms             | 13.9±2ms            | 1.02    | load.LoadAndRealise.time_realise((1280, 960, 5), False, 'PP')                               |
|          | 25.6±0.7ms           | 25.7±2ms            | 1.01    | load.LoadAndRealise.time_realise((1280, 960, 5), True, 'FF')                                |
|          | 70.6±2ms             | 70.6±2ms            | 1.00    | load.LoadAndRealise.time_realise((1280, 960, 5), True, 'NetCDF')                            |
|          | 25.4±0.8ms           | 26.1±2ms            | 1.03    | load.LoadAndRealise.time_realise((1280, 960, 5), True, 'PP')                                |
|          | 440±4ms              | 491±2ms             | 1.12    | load.LoadAndRealise.time_realise((2, 2, 1000), False, 'FF')                                 |
|          | 2.81±0.08ms          | 3.00±0.07ms         | 1.07    | load.LoadAndRealise.time_realise((2, 2, 1000), False, 'NetCDF')                             |
|          | 444±3ms              | 498±3ms             | 1.12    | load.LoadAndRealise.time_realise((2, 2, 1000), False, 'PP')                                 |
|          | 445±3ms              | 498±2ms             | 1.12    | load.LoadAndRealise.time_realise((2, 2, 1000), True, 'FF')                                  |
|          | 2.87±0.1ms           | 2.98±0.1ms          | 1.04    | load.LoadAndRealise.time_realise((2, 2, 1000), True, 'NetCDF')                              |
|          | 450±3ms              | 503±2ms             | 1.12    | load.LoadAndRealise.time_realise((2, 2, 1000), True, 'PP')                                  |
|          | 1.53±0.07ms          | 1.74±0.07ms         | 1.13    | load.LoadAndRealise.time_realise((50, 50, 2), False, 'FF')                                  |
|          | 2.81±0.1ms           | 2.89±0.08ms         | 1.03    | load.LoadAndRealise.time_realise((50, 50, 2), False, 'NetCDF')                              |
|          | 1.62±0.09ms          | 1.68±0.06ms         | 1.04    | load.LoadAndRealise.time_realise((50, 50, 2), False, 'PP')                                  |
|          | 1.61±0.08ms          | 1.72±0.05ms         | 1.07    | load.LoadAndRealise.time_realise((50, 50, 2), True, 'FF')                                   |
|          | 2.93±0.1ms           | 3.01±0.09ms         | 1.03    | load.LoadAndRealise.time_realise((50, 50, 2), True, 'NetCDF')                               |
|          | 1.59±0.08ms          | 1.71±0.09ms         | 1.08    | load.LoadAndRealise.time_realise((50, 50, 2), True, 'PP')                                   |
|          | 370±4ms              | 371±4ms             | 1.00    | load.ManyVars.time_many_var_load                                                            |
|          | 8.26±0.03ms          | 9.21±0.07ms         | 1.12    | load.STASHConstraint.time_stash_constraint((1280, 960, 5), 'FF')                            |
|          | 9.02±0.07ms          | 10.1±0.06ms         | 1.12    | load.STASHConstraint.time_stash_constraint((1280, 960, 5), 'PP')                            |
|          | 1.37±0.01s           | 1.58±0.01s          | 1.16    | load.STASHConstraint.time_stash_constraint((2, 2, 1000), 'FF')                              |
|          | 1.55±0.01s           | 1.74±0.01s          | 1.12    | load.STASHConstraint.time_stash_constraint((2, 2, 1000), 'PP')                              |
|          | 3.99±0.03ms          | 4.38±0.01ms         | 1.10    | load.STASHConstraint.time_stash_constraint((2, 2, 2), 'FF')                                 |
|          | 4.26±0.04ms          | 4.70±0.06ms         | 1.10    | load.STASHConstraint.time_stash_constraint((2, 2, 2), 'PP')                                 |
|          | 8.21±0.1ms           | 9.19±0.09ms         | 1.12    | load.StructuredFF.time_structured_load((1280, 960, 5), False)                               |
|          | 5.03±0.08ms          | 5.96±0.03ms         | 1.18    | load.StructuredFF.time_structured_load((1280, 960, 5), True)                                |
|          | 1.35±0.01s           | 1.55±0.01s          | 1.15    | load.StructuredFF.time_structured_load((2, 2, 1000), False)                                 |
|          | 3.92±0.08ms          | 4.32±0.05ms         | 1.10    | load.StructuredFF.time_structured_load((2, 2, 2), False)                                    |
|          | 3.82±0.04ms          | 4.20±0.04ms         | 1.10    | load.StructuredFF.time_structured_load((2, 2, 2), True)                                     |
|          | 148±1ms              | 165±1ms             | 1.11    | load.TimeConstraint.time_time_constraint(20, 'FF')                                          |
|          | 23.8±0.2ms           | 24.2±0.2ms          | 1.02    | load.TimeConstraint.time_time_constraint(20, 'NetCDF')                                      |
|          | 163±0.9ms            | 181±1ms             | 1.11    | load.TimeConstraint.time_time_constraint(20, 'PP')                                          |
|          | 29.3±0.3ms           | 32.0±0.2ms          | 1.09    | load.TimeConstraint.time_time_constraint(3, 'FF')                                           |
|          | 23.2±0.2ms           | 23.8±0.2ms          | 1.03    | load.TimeConstraint.time_time_constraint(3, 'NetCDF')                                       |
|          | 31.7±0.1ms           | 34.4±0.2ms          | 1.09    | load.TimeConstraint.time_time_constraint(3, 'PP')                                           |
|          | 17.6±0.3ms           | 18.8±0.6ms          | 1.07    | load.ugrid.BasicLoading.time_load_file(1)                                                   |
|          | 41.1±0.5ms           | 45.6±1ms            | 1.11    | load.ugrid.BasicLoading.time_load_file(200000)                                              |
|          | 14.4±0.1ms           | 15.4±0.2ms          | 1.07    | load.ugrid.BasicLoading.time_load_mesh(1)                                                   |
|          | 21.9±0.5ms           | 23.7±0.4ms          | 1.08    | load.ugrid.BasicLoading.time_load_mesh(200000)                                              |
|          | 18.1±0.3ms           | 18.4±0.4ms          | 1.01    | load.ugrid.BasicLoadingTime.time_load_file(1)                                               |
|          | 20.2±0.6ms           | 21.6±0.5ms          | 1.07    | load.ugrid.BasicLoadingTime.time_load_file(200000)                                          |
|          | 14.4±0.3ms           | 14.9±0.3ms          | 1.03    | load.ugrid.BasicLoadingTime.time_load_mesh(1)                                               |
|          | 16.7±0.2ms           | 17.4±0.3ms          | 1.04    | load.ugrid.BasicLoadingTime.time_load_mesh(200000)                                          |
|          | 18.7±0.4ms           | 19.2±0.5ms          | 1.03    | load.ugrid.Callback.time_load_file_callback(1)                                              |
|          | 50.6±0.8ms           | 56.3±0.5ms          | 1.11    | load.ugrid.Callback.time_load_file_callback(200000)                                         |
|          | 18.8±0.3ms           | 19.4±0.5ms          | 1.04    | load.ugrid.CallbackTime.time_load_file_callback(1)                                          |
|          | 22.1±0.4ms           | 22.9±0.4ms          | 1.03    | load.ugrid.CallbackTime.time_load_file_callback(200000)                                     |
|          | 2.73±0.08ms          | 2.86±0.1ms          | 1.05    | load.ugrid.DataRealisation.time_realise_data(10000)                                         |
|          | 5.41±0.9ms           | 5.54±0.08ms         | 1.03    | load.ugrid.DataRealisation.time_realise_data(200000)                                        |
|          | 37.7±0.9ms           | 37.9±1ms            | 1.00    | load.ugrid.DataRealisationTime.time_realise_data(10000)                                     |
|          | 808±4ms              | 806±50ms            | 1.00    | load.ugrid.DataRealisationTime.time_realise_data(200000)                                    |
|          | 397±4ms              | 442±7ms             | 1.11    | merge_concat.Concatenate.time_concatenate(False)                                            |
|          | 396±3ms              | 440±5ms             | 1.11    | merge_concat.Concatenate.time_concatenate(True)                                             |
|          | 109±0.5M             | 109±0.2M            | 1.00    | merge_concat.Concatenate.tracemalloc_concatenate(False)                                     |
|          | 109±0.5M             | 109±0.2M            | 1.00    | merge_concat.Concatenate.tracemalloc_concatenate(True)                                      |
|          | 48.3±0.7ms           | 52.5±1ms            | 1.09    | merge_concat.Merge.time_merge                                                               |
|          | 1±0.3M               | 1.21±0.09M          | ~1.21   | merge_concat.Merge.tracemalloc_merge                                                        |
|          | 388±2ns              | 409±5ns             | 1.05    | mesh.utils.regions_combine.CombineRegionsComputeRealData.time_compute_data(50)              |
|          | 258±1ms              | 258±2ms             | 1.00    | mesh.utils.regions_combine.CombineRegionsComputeRealData.time_compute_data(500)             |
|          | 647±2k               | 650±2k              | 1.01    | mesh.utils.regions_combine.CombineRegionsComputeRealData.tracemalloc_compute_data(50)       |
|          | 60±0M                | 60.1±0M             | 1.00    | mesh.utils.regions_combine.CombineRegionsComputeRealData.tracemalloc_compute_data(500)      |
|          | 14.5±0.2ms           | 17.1±0.09ms         | 1.18    | mesh.utils.regions_combine.CombineRegionsCreateCube.time_create_combined_cube(50)           |
|          | 16.3±0.2ms           | 18.9±0.2ms          | 1.16    | mesh.utils.regions_combine.CombineRegionsCreateCube.time_create_combined_cube(500)          |
|          | 507±90k              | 517±90k             | 1.02    | mesh.utils.regions_combine.CombineRegionsCreateCube.tracemalloc_create_combined_cube(50)    |
|          | 12.4±0.09M           | 12.4±0.09M          | 1.00    | mesh.utils.regions_combine.CombineRegionsCreateCube.tracemalloc_create_combined_cube(500)   |
|          | 107±1ms              | 109±1ms             | 1.02    | mesh.utils.regions_combine.CombineRegionsFileStreamedCalc.time_stream_file2file(50)         |
|          | 701±9ms              | 704±4ms             | 1.00    | mesh.utils.regions_combine.CombineRegionsFileStreamedCalc.time_stream_file2file(500)        |
|          | 1.22±0.03M           | 1.23±0.03M          | 1.01    | mesh.utils.regions_combine.CombineRegionsFileStreamedCalc.tracemalloc_stream_file2file(50)  |
|          | 96.3±0.04M           | 96.3±0.05M          | 1.00    | mesh.utils.regions_combine.CombineRegionsFileStreamedCalc.tracemalloc_stream_file2file(500) |
|          | 66.9±0.7ms           | 69.8±0.8ms          | 1.04    | mesh.utils.regions_combine.CombineRegionsSaveData.time_save(50)                             |
|          | 658±4ms              | 659±3ms             | 1.00    | mesh.utils.regions_combine.CombineRegionsSaveData.time_save(500)                            |
|          | 1.15±0.02M           | 1.14±0.01M          | 0.99    | mesh.utils.regions_combine.CombineRegionsSaveData.tracemalloc_save(50)                      |
|          | 96.2±0.02M           | 96.2±0.03M          | 1.00    | mesh.utils.regions_combine.CombineRegionsSaveData.tracemalloc_save(500)                     |
|          | 2.1752849999999997   | 2.1752849999999997  | 1.00    | mesh.utils.regions_combine.CombineRegionsSaveData.track_filesize_saved(50)                  |
|          | 216.01528499999998   | 216.01528499999998  | 1.00    | mesh.utils.regions_combine.CombineRegionsSaveData.track_filesize_saved(500)                 |
|          | 6.57±0.05ms          | 6.73±0.04ms         | 1.02    | plot.AuxSort.time_aux_sort                                                                  |
|          | 76.7±2ms             | 78.3±3ms            | 1.02    | regridding.CurvilinearRegridding.time_regrid_pic                                            |
|          | 136±3M               | 136±3M              | 1.00    | regridding.CurvilinearRegridding.tracemalloc_regrid_pic                                     |
|          | 99.1±1ms             | 98.6±2ms            | 0.99    | regridding.HorizontalChunkedRegridding.time_regrid_area_w                                   |
|          | 49.9±3ms             | 50.0±6ms            | 1.00    | regridding.HorizontalChunkedRegridding.time_regrid_area_w_new_grid                          |
|          | 106±0.06M            | 106±0.05M           | 1.00    | regridding.HorizontalChunkedRegridding.tracemalloc_regrid_area_w                            |
|          | 147±0.6M             | 147±0.02M           | 1.00    | regridding.HorizontalChunkedRegridding.tracemalloc_regrid_area_w_new_grid                   |
|          | 4.09±0.07ms          | 4.58±0.07ms         | 1.12    | save.NetcdfSave.time_netcdf_save_cube(50, False)                                            |
|          | 72.6±0.8ms           | 74.8±1ms            | 1.03    | save.NetcdfSave.time_netcdf_save_cube(50, True)                                             |
|          | 52.4±0.7ms           | 53.1±0.9ms          | 1.01    | save.NetcdfSave.time_netcdf_save_cube(600, False)                                           |
|          | 561±2ms              | 567±9ms             | 1.01    | save.NetcdfSave.time_netcdf_save_cube(600, True)                                            |
|          | 89.1±0.9ns           | 88.8±0.4ns          | 1.00    | save.NetcdfSave.time_netcdf_save_mesh(50, False)                                            |
|          | 55.9±0.7ms           | 57.6±1ms            | 1.03    | save.NetcdfSave.time_netcdf_save_mesh(50, True)                                             |
|          | 89.9±0.4ns           | 90.9±1ns            | 1.01    | save.NetcdfSave.time_netcdf_save_mesh(600, False)                                           |
|          | 494±2ms              | 495±8ms             | 1.00    | save.NetcdfSave.time_netcdf_save_mesh(600, True)                                            |
|          | 27.2±0.1k            | 28.6±0.06k          | 1.05    | save.NetcdfSave.tracemalloc_netcdf_save(50, False)                                          |
|          | 1.52±0.1M            | 1.66±0.1M           | 1.09    | save.NetcdfSave.tracemalloc_netcdf_save(50, True)                                           |
|          | 27.2±0.1k            | 28.6±0.09k          | 1.05    | save.NetcdfSave.tracemalloc_netcdf_save(600, False)                                         |
|          | 216±20M              | 199±20M             | 0.92    | save.NetcdfSave.tracemalloc_netcdf_save(600, True)                                          |
|          | 42.7±1ms             | 48.1±1ms            | 1.13    | stats.PearsonR.time_lazy                                                                    |
|          | 19.1±0.3ms           | 19.2±0.4ms          | 1.00    | stats.PearsonR.time_real                                                                    |
|          | 20±0.08M             | 20±0.08M            | 1.00    | stats.PearsonR.tracemalloc_lazy                                                             |
|          | 18.4±0.01M           | 18.4±0.01M          | 1.00    | stats.PearsonR.tracemalloc_real                                                             |
|          | 23.0±2ms             | 23.4±0.5ms          | 1.01    | trajectory.TrajectoryInterpolation.time_trajectory_linear                                   |
|          | 61.3±0.4ms           | 62.1±0.7ms          | 1.01    | trajectory.TrajectoryInterpolation.time_trajectory_nearest                                  |
|          | 23.3±0.01M           | 23.3±0.01M          | 1.00    | trajectory.TrajectoryInterpolation.tracemalloc_trajectory_linear                            |
|          | 12.1±0.05M           | 12.1±0.05M          | 1.00    | trajectory.TrajectoryInterpolation.tracemalloc_trajectory_nearest                           |

Benchmarks that have got worse:

| Change   | Before [1a9bdaa5]    | After [f04064e7]    |   Ratio | Benchmark (Parameter)                                      |
|----------|----------------------|---------------------|---------|------------------------------------------------------------|
| +        | 370±2ms              | 548±3ms             |    1.48 | load.StructuredFF.time_structured_load((2, 2, 1000), True) |

Generated by GHA run 10705932987

[pp-mo]

Also tested : a "minimal" noxfile like this :

import nox

#: Default to reusing any pre-existing nox environments.
nox.options.reuse_existing_virtualenvs = False  # was True for Iris


def show_env(session: nox.sessions.Session):
    session.run("echo", '"NOX TEST LIVE-ENV DUMP == START "', external=True)
    session.run("env", external=True)
    session.run("echo", '".. == END NOX TEST LIVE-ENV DUMP."', external=True)
    session.run("echo", 'NOX TEST session env."', external=True)
    msg = "\n".join(("  " + str(item)) for item in session.env.items())
    print(msg)
    session.run("echo", '.. = END NOX TEST session env."', external=True)


@nox.session(venv_backend="conda")
def basic(session: nox.sessions.Session):
    show_env(session)

@nox.session(venv_backend="conda")
def withproj(session: nox.sessions.Session):
    session.conda_install("proj", "pyproj")
    show_env(session)

Results

Too long+tedious to copy here, but it suffices to say that PROJ_DATA is not set in the environment where proj is installed.

Checking the nox code, I believe that the Session.conda_install() call eventually calls popen, setting any specific variables from session.env, but there is no effort to capture any env changes that the install makes.
I have also checked that the user "conda install" does set env variables, i.e. effectively it actions activation scripts just like "conda activate" does.

So I conclude that nox.Session.conda_install() just does not support additional activation steps.
This is how an unsuitable PROJ_DATA setting manages to upset the installation of a later version of proj.

However, consulting also our SSS modulefiles, which likewise include variables from activation scripts so as to mimic a "conda activate", it seems that PROJ_DATA is quite possibly the only one which is likely to cause trouble in this way. So in practice it's a marginal problem.

In this specific case, another way to fix it could be to set PROJ_DATA="invalid", since Proj seems to ignore any value which is not a suitable filepath. I think you can do that by setting session.env["PROJ_DATA"] = "invalid" in the nox code