Pin libzlib as well as / instead of zlib

[jmarshall]

• I read the conda-forge documentation and could not find the solution for my problem there.

The zlib runtime was recently (conda-forge/zlib-feedstock#52) split into a new libzlib subpackage. This repository's recipe/conda_build_config.yaml lists pinning for zlib; does it need to be updated to list a pinning for libzlib instead / as well?

I noticed while developing an update to a package I help maintain that zlib no longer contributed to the package hash (see also previous build in which it did — scroll to the bottom):

14:13:56 BIOCONDA INFO (OUT) INFO :: The inputs making up the hashes for the built packages are as follows:
14:13:56 BIOCONDA INFO (OUT) {
14:13:56 BIOCONDA INFO (OUT)   "htslib-1.13-ha0adc58_4": {
14:13:56 BIOCONDA INFO (OUT)     "recipe": {
14:13:56 BIOCONDA INFO (OUT)       "CONDA_BUILD_SYSROOT": "",
                                   [… no  "zlib": "1.2"  as previously …]
14:13:56 BIOCONDA INFO (OUT)     }
14:13:56 BIOCONDA INFO (OUT)   },

It appears from the comment at https://github.com/conda/conda-build/blob/174ed2000f5a7ac05d1c743bb38f4a40d647e6bb/conda_build/metadata.py#L1294-L1299 that this may be because libzlib does not appear in the relevant conda_build_config.yaml, which I believe is the one from this repository.

[jakirkham]

cc @conda-forge/core (for awareness)

[isuruf]

You can't use libzlib standalone in host. You have to use zlib in host which means it will be used in the hash.