Merge pull request #2522 from h-vetinari/numpy

Add announcement for closing numpy 2.0 migration

Author: h-vetinari

docs/maintainer/knowledge_base.md

@@ -533,9 +533,10 @@ requirements:
     - numpy
   run:
     - python
-    - {{ pin_compatible("numpy") }}
 ```
 
+For more details about numpy see the dedicated [section](#building-against-numpy).
+
 With MPI, openmpi is required for the build platform as the compiler wrappers are binaries, but mpich is not required as the compiler wrappers are scripts (see [example](https://github.com/conda-forge/mpi4py-feedstock/blob/743d379c4a04/recipe/meta.yaml#L37)):
 
 ```yaml
@@ -770,36 +771,23 @@ host:
   - numpy
 ```
 
-At the time of writing (January, 2025), above is equivalent to the following,
-
-```yaml
-host:
-  - numpy   1.22   # [py==39]
-  - numpy   1.22   # [py==310]
-  - numpy   1.23   # [py==311]
-  - numpy   1.26   # [py==312]
-```
-
-though the ongoing migration for numpy 2.0 has already been applied to many
-feedstocks, in which case the pinning looks like
+At the time of writing (June 2025), above is equivalent to the following,
 
-```yaml
+```yaml title="recipe/conda_build_config.yaml"
 host:
-  - numpy   2.0    # [py==39]
-  - numpy   2.0    # [py==310]
-  - numpy   2.0    # [py==311]
-  - numpy   2.0    # [py==312]
+  - numpy 2.*
 ```
 
-See the pinning repository for what the pinning corresponds to at time of writing
-[https://github.com/conda-forge/conda-forge-pinning-feedstock/blob/main/recipe/conda_build_config.yaml#L742](https://github.com/conda-forge/conda-forge-pinning-feedstock/blob/main/recipe/conda_build_config.yaml#L742)
+See the pinning repository for
+[what the pinning corresponds to](https://github.com/conda-forge/conda-forge-pinning-feedstock/blob/main/recipe/conda_build_config.yaml#L742) at any given time.
 
 In either case, the actual runtime requirements are determined through numpy's
 run-export, which is:
 
 - `>=1.2x,<2` if you're building against numpy 1.2x
 - `>=1.19,<3` if you're building against numpy 2.0
 - `>=1.21,<3` if you're building against numpy 2.1 or 2.2
+- `>=1.23,<3` if you're building against numpy 2.3
 
 If the package you are building has a higher minimum requirement for numpy, please add this under `run`:
 

news/2025-05-28-numpy-2-migration-closure.md

@@ -0,0 +1,19 @@
+# Upcoming closure of NumPy 2.0 migration
+
+NumPy 2.0 was a big change (the first major version in 15 years). For more than a year, we
+have been migrating feedstocks from NumPy 1.x to NumPy 2.x, and while not every affected
+feedstock has been done, we are planning to conclude the migration in one week.
+Note that NumPy 2 support is required for feedstocks that intend to support Python 3.13
+and above.
+
+For feedstocks that are not compatible with v2.x yet, this means you will have to add
+
+```yaml
+numpy:
+  - 1.26  # or 1.25
+```
+
+to your `recipe/conda_build_config.yaml`, and then rerender. Pins below 1.25 are not possible
+if your feedstock supports Python 3.12, as NumPy 1.25 was the first version with support for
+that Python version (and it will not be possible going forward to pin different NumPy versions
+for different Python versions).