Support linux-riscv64 platform + Use default c_stdlib_version on linux-riscv64

.ci_support/linux_riscv64_.yaml

@@ -0,0 +1,28 @@
+c_compiler:
+- gcc
+c_compiler_version:
+- '15'
+c_stdlib:
+- sysroot
+c_stdlib_version:
+- '2.39'
+channel_sources:
+- conda-forge
+channel_targets:
+- conda-forge main
+docker_image:
+- quay.io/condaforge/linux-anvil-x86_64:alma10
+ncurses:
+- '6'
+pin_run_as_build:
+  python:
+    min_pin: x.x
+    max_pin: x.x
+python:
+- 3.14.* *_cp314
+readline:
+- '8'
+target_platform:
+- linux-riscv64
+zlib:
+- '1'

.github/workflows/conda-build.yml

@@ -166,6 +166,18 @@ jobs:
             resize_partitions: False
             runs_on: ['ubuntu-latest']
             tools_install_dir: ~/miniforge3
+          - CONFIG: linux_riscv64_
+            DOCKER_IMAGE: quay.io/condaforge/linux-anvil-x86_64:alma10
+            STORE_BUILD_ARTIFACTS: False
+            UPLOAD_PACKAGES: True
+            build_workspace_dir: build_artifacts
+            docker_run_args: 
+            free_disk_space: skip
+            os: ubuntu
+            pagefile_size: 0
+            resize_partitions: False
+            runs_on: ['ubuntu-latest']
+            tools_install_dir: ~/miniforge3
     steps:
 
     - name: Checkout code

conda-forge.yml

@@ -3,6 +3,7 @@ bot:
 build_platform:
   linux_aarch64: linux_64
   linux_ppc64le: linux_64
+  linux_riscv64: linux_64
   osx_arm64: osx_64
 conda_build:
   pkg_format: '2'

recipe/build.sh

@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# Get an updated config.sub and config.guess
+cp $BUILD_PREFIX/share/gnuconfig/config.* ./config
 set -ex
 
 OSX_ARGS=""

recipe/conda_build_config.yaml

@@ -1,2 +1,2 @@
-c_stdlib_version:          # [linux]
-  - "2.28"                 # [linux]
+c_stdlib_version:          # [linux and not riscv64]
+  - "2.28"                 # [linux and not riscv64]

recipe/meta.yaml

@@ -13,7 +13,7 @@ source:
     - 4554-kill-decode-strip-RT0.patch
 
 build:
-  number: 2
+  number: 3
   skip: true  # [not unix]
   run_exports:
     - {{ pin_subpackage('util-linux', max_pin='x.x') }}
@@ -23,6 +23,7 @@ requirements:
     - python                                 # [build_platform != target_platform]
     - cross-python_{{ target_platform }}     # [build_platform != target_platform]
     - gnuconfig  # [unix]
+    - gnuconfig  # [unix]
     - {{ compiler('c') }}
     - {{ stdlib('c') }}
     - make