Starting this week, we are changing the way we upload packages to anaconda.org. We will move from direct uploads to the conda-forge main channel to using a staging organization/channel combined with a copy request from the staging channel to the production channel. This new process will allow us to perform some validation on the outputs of feedstocks before they are released.

What will you see as a feedstock maintainer?

• Starting this week, the admin-migrations service will be making commits to all feedstocks to provision them with the necessary configuration, API keys, and tokens.
• Each feedstock will now be provisioned with a secret token. This token should not be shared or taken out of the CI services. It is used to identify the feedstock during the upload process.
• The admin-migrations service will be setting a new top-level key in the conda-forge.yml, conda_forge_output_validation: true. This key indicates to conda-smithy that it should include the output validation calls in the feedstock CI scripts.
• Currently open PRs will need to have this key added by hand and then rerendered.
• When PRs are running the CI scripts, they will do some initial validation of the feedstock outputs. If this validation fails, the CI job will fail. Please see the CI logs for the error message which is printed after conda-build runs.
• Once a PR is merged to master, the copy from the staging channel to the production channel will happen automatically.
• Should a copy request fail, you will get a notification via a comment on the commit to master.
• As part of this process, uploads from appveyor will no longer be allowed unless there is a significant barrier to using azure. We have recently upgraded the compiler infrastructure on azure to support this change in policy.

Despite our extensive testing, we do not expect this change to be completely smooth, so please bear with us. As always, if you have any questions, concerns, or trouble, you can find us on Gitter or bump us directly on Github!

We are formally deprecating vs2015 in two weeks on 2020-04-07 and will move to vs2017. This change will enable us to support the usage of msbuild on Azure for the win platform and will provide additional support for C++. Most packages built with vs2015 can be linked with vs2017 toolchain (but not vice-versa). An exception is static libraries compiled with whole program optimization (/GL flag) which may be incompatible with the vs2017 toolchain. These static libraries will need to be rebuilt using vs2017.

We are now starting to formally deprecate Appveyor in favor of Azure for builds on the win platform. Note that we have not been adding appveyor to new feedstocks for a while, so this is not a completely new change in policy. We will now, however, begin to actively disable Appveyor builds on feedstocks not using it by turning off builds for GitHub push events. Additionally, we have been issuing PRs to any remaining feedstocks to move them to Azure. We are aware that some packages built with msbuild cannot yet be moved to Azure and so are leaving Appveyor on for those feedstocks for now.

A webservices admin command is now available to add Python 2.7 back to feedstocks. Put @conda-forge-admin add python 2.7 in the title on an issue in your feedstock. The admin webservices bot will then issue a PR adding back Python 2.7. Note that this PR will remove other Python builds and any win, aarch64, or ppc64le builds. If you want to keep those, merge the PR into a separate branch on your feedstock.

• Python 2.7 is no longer supported by the upstream developers as of 2020-01-01. Conda-forge is thus deprecating its Python 2.7 support. Conda-forge will provide no ongoing support for Python 2.7 builds and any existing builds are provided on an "as-is" basis.
• A cf202003 label has been applied to the conda-forge channel for those who need a reference to the package index with Python 2.7.
• We are removing support for vs2008 on Windows in conjunction with the deprecation of Python 2.7, as it was only supported to build this version of Python.
• We will provide an admin command that will add back Python 2.7 to any feedstock. Note that as stated above, we cannot provide support for any Python 2.7 builds generated with this admin command. Further, this admin command will only work on osx-64 and linux-64 platforms.

• If you maintain a feedstock that requires a C/C++ compiler, no changes necessary. A rerender should be done next time the feedstock is updated to use the new compiler.
• If you maintain a feedstock with a Fortran compiler, a PR to upgrade to gfortran 7.3.0 was already issued. If that PR was merged, there's nothing to do. If not, contact core if you need help migrating.

• Our packages now build against NETLIB’s reference implementation.
• You as a user can now choose the implementation available at runtime. For more information please refer to the documentation.

If you:

• maintain a compiled feedstock, it will likely need to be rerender
• need to roll back to the old compilers, you can use the "cf201901" label.

Recently completed are NumPy and Openblas which should open up much of the python numeric stack. We're only about 5 feedstocks away from opening up all of R as well.

Yay!