Create an announcement on <linkxlink:href="https://discourse.nixos.org">Discourse</link> as a warning about upcoming beta <quote>feature freeze</quote> in a month. <linkxlink:href="https://discourse.nixos.org/t/nixos-19-09-feature-freeze/3707">See this post as an example</link>.
Discuss with Eelco Dolstra and the community (via IRC, ML) about what will reach the deadline. Any issue or Pull Request targeting the release should be included in the release milestone.
</para>
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<listitem>
<para>
Remove attributes that we know we will not be able to support, especially if there is a stable alternative. E.g. Check that our Linux kernels’<linkxlink:href="https://www.kernel.org/category/releases.html">projected end-of-life</link> are after our release projected end-of-life.
<linkxlink:href="https://github.com/NixOS/nixpkgs/commit/10e61bf5be57736035ec7a804cb0bf3d083bf2cf#diff-9c798092bac0caeb5c52d509be0ca263R69">Bump the <literal>system.defaultChannel</literal> attribute in <literal>nixos/modules/misc/version.nix</literal></link>
<linkxlink:href="https://github.com/NixOS/nixpkgs/commit/10e61bf5be57736035ec7a804cb0bf3d083bf2cf#diff-831e8d9748240fb23e6734fdc2a6d16eR15">Update <literal>versionSuffix</literal> in <literal>nixos/release.nix</literal></link>
<linkxlink:href="https://github.com/NixOS/nixpkgs/commit/01268fda85b7eee4e462c873d8654f975067731f#diff-2bc0e46110b507d6d5a344264ef15adaR1">On the <literal>master</literal> branch, increment the <literal>.version</literal> file</link>
<linkxlink:href="https://github.com/NixOS/nixpkgs/commit/01268fda85b7eee4e462c873d8654f975067731f#diff-03f3d41b68f62079c55001f1a1c55c1dR137">Update <literal>codeName</literal> in <literal>lib/trivial.nix</literal></link> This will be the name for the next release.
<linkxlink:href="https://github.com/NixOS/nixpkgs/commit/01268fda85b7eee4e462c873d8654f975067731f#diff-e7ee5ff686cdcc513ca089d6e5682587R11">Create a new release notes file for the upcoming release + 1</link>, in our case this is <literal>rl-2003.xml</literal>.
<linkxlink:href="https://github.com/NixOS/nixos-org-configurations/blob/master/channels.nix">Create a channel at https://nixos.org/channels by creating a PR to nixos-org-configurations, changing <literal>channels.nix</literal></link>
<linkxlink:href="https://github.com/NixOS/nixpkgs/issues/13559">Create an issue for tracking Zero Hydra Failures progress. ZHF is an effort to get build failures down to zero.</link>
Release Nix (currently only Eelco Dolstra can do that). <linkxlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/installer/tools/nix-fallback-paths.nix">Make sure fallback is updated.</link>
<linkxlink:href="https://github.com/NixOS/nixpkgs/commit/40fd9ae3ac8048758abdcfc7d28a78b5f22fe97e">Update README.md with new stable NixOS version information.</link>
git tag --annotate --message="Release 19.09" 19.09
git push upstream 19.09
</programlisting>
</listitem>
<listitem>
<para>
Update <linkxlink:href="https://github.com/NixOS/nixos-homepage">nixos-homepage</link> for the release.
</para>
<orderedlist>
<listitem>
<para>
<linkxlink:href="https://github.com/NixOS/nixos-homepage/blob/47ac3571c4d71e841fd4e6c6e1872e762b9c4942/Makefile#L1">Update <literal>NIXOS_SERIES</literal> in the <literal>Makefile</literal></link>.
</para>
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<listitem>
<para>
<linkxlink:href="https://github.com/NixOS/nixos-homepage/blob/47ac3571c4d71e841fd4e6c6e1872e762b9c4942/nixos-release.tt#L1">Update <literal>nixos-release.tt</literal> with the new NixOS version</link>.
</para>
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<listitem>
<para>
<linkxlink:href="https://github.com/NixOS/nixos-homepage/blob/47ac3571c4d71e841fd4e6c6e1872e762b9c4942/flake.nix#L10">Update the <literal>flake.nix</literal> input <literal>released-nixpkgs</literal> to 19.09</link>.
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<listitem>
<para>
Run <literal>./update.sh</literal> (this updates flake.lock to updated channel).
</para>
</listitem>
<listitem>
<para>
<linkxlink:href="https://github.com/NixOS/nixos-homepage/blob/a5626c71c03a2dd69086564e56f1a230a2bb177a/logo/nixos-logo-19.09-loris-lores.png">Add a compressed version of the NixOS logo for 19.09</link>.
</para>
</listitem>
<listitem>
<para>
<linkxlink:href="https://github.com/NixOS/nixos-homepage/commit/a5626c71c03a2dd69086564e56f1a230a2bb177a#diff-9cdc6434d3e4fd93a6e5bb0a531a7c71R5">Compose a news item for the website RSS feed</link>.
For each release there are two release managers. After each release the release manager having managed two releases steps down and the release management team of the last release appoints a new release manager.
This makes sure a release management team always consists of one release manager who already has managed one release and one release manager being introduced to their role, making it easier to pass on knowledge and experience.
Release managers for the current NixOS release are tracked by GitHub team <linkxlink:href="https://github.com/orgs/NixOS/teams/nixos-release-managers/members"><literal>@NixOS/nixos-release-managers</literal></link>.