run_exports from channeldata.json not always applied

[jjhelmus]

Using conda 3.18.7 run_exports are not reliably applied to recipes.

For example:

package:
  name: example
  version: 1.0

requirements:
  build:
    - {{ compiler('c') }}

Rendering this recipe repeatedly gives two different results, the second one in this example is correct.

[root@chi9 io]# conda build --version
conda-build 3.18.7
[root@chi9 io]# conda render .
--------------
Hash contents:
--------------
{'c_compiler': 'gcc'}
----------
meta.yaml:
----------
package:
    name: example
    version: '1.0'
requirements:
    build:
        - _libgcc_mutex 0.1 main
        - binutils_impl_linux-64 2.31.1 h6176602_1
        - libstdcxx-ng 9.1.0 hdf63c60_0
        - binutils_linux-64 2.31.1 h6176602_7
        - libgcc-ng 9.1.0 hdf63c60_0
        - gcc_impl_linux-64 7.3.0 habb00fd_1
        - gcc_linux-64 7.3.0 h553295d_7
extra:
    copy_test_source_files: true
    final: true

[root@chi9 io]# conda render .
--------------
Hash contents:
--------------
{'c_compiler': 'gcc'}
----------
meta.yaml:
----------
package:
    name: example
    version: '1.0'
requirements:
    build:
        - _libgcc_mutex 0.1 main
        - libgcc-ng 9.1.0 hdf63c60_0
        - binutils_linux-64 2.31.1 h6176602_7
        - binutils_impl_linux-64 2.31.1 h6176602_1
        - gcc_impl_linux-64 7.3.0 habb00fd_1
        - gcc_linux-64 7.3.0 h553295d_7
        - libstdcxx-ng 9.1.0 hdf63c60_0
    host:
        - _libgcc_mutex 0.1 main
        - libgcc-ng 9.1.0 hdf63c60_0
    run:
        - libgcc-ng >=7.3.0
extra:
    copy_test_source_files: true
    final: true

From my limited debugging this seems to depend on the order in which the channeldata is read in for the sub-channels of defaults in the download_channel function. If main is read in last the correct run_exports are applied, if r then the results are incorrect.

Likely related to some of the comments in #3583

[github-actions]

Hi there, thank you for your contribution!

This issue has been automatically locked because it has not had recent activity after being closed.

Please open a new issue if needed.

Thanks!