update doc for local builds of conda-forge recipes

doc/maintainers/sparc-c-c++.md

@@ -121,6 +121,16 @@ create the PR yourself). After confirming that all the checks have
 passed, you can merge the pull request to include the compiled
 binaries in the conda-forge channel.
 
+### Debug the recipe using local build
+
+Building the recipe locally is identical to the steps for [`sparc-x-api-feedstock`](#conda-forge-build-locally-api).
+You need
+both the [docker engine](https://docs.docker.com/engine/) and a [conda distribution](https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html) installed on your local
+machine, and run the following command at the root of the local clone of `sparc-x-feedstock`:
+```{code} bash
+python build-locally.py
+```
+
 ### Revised builds
 
 If by any chance you find the newly released SPARC binaries in
@@ -140,7 +150,9 @@ build:
   number: 1
 ```
 
-This allows conda-forge to distinguish two builds without affecting the version number, as the actual package is named like `<os>-<arch>/sparc-x-2.0.0-<hash>_<build>.conda`.
+This allows conda-forge to distinguish two builds without affecting
+the version number, as the actual package is named like
+`<os>-<arch>/sparc-x-2.0.0-<hash>_<build>.conda`.
 
 ```{note}
 If the error stems from the C/C++ itself, you should update the release in the SPARC github repo instead.

doc/maintainers/sparc-x-api.md

@@ -21,6 +21,18 @@ for the maintainers to modify and merge. Please also ensure:
 - Do not directly use the [`.conda/meta.yaml`](https://github.com/SPARC-X/SPARC-X-API/blob/master/.conda/meta.yaml) for conda-forge (it is designed for local packaging test)
 - Bump the `build.number` if you need to change the recipe YAML on the same SPARC-X-API release.
 
+(conda-forge-build-locally-api)=
+### Debug the recipe using local build
+
+The build toolchain in conda-forge is slightly different from the
+standard `conda-build` command. If the build workflow fails after
+submitting the PR, you may run the recipe locally to debug. You need
+both the [docker engine](https://docs.docker.com/engine/) and a [conda distribution](https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html) on your local
+machine. Run the following command at the root of the local clone of `sparc-x-api-feedstock`:
+```{code} bash
+python build-locally.py
+```
+
 ## Deploy on PyPI
 
 SPARC-X-API is deployed on PyPI under the name