# Breaking changes announcement for unstable
**URL:** https://discourse.nixos.org/t/breaking-changes-announcement-for-unstable/17574
**Category:** Development
**Created:** [February 8, 2022, 11:18am UTC](https://discourse.nixos.org/t/breaking-changes-announcement-for-unstable/17574 "2022-02-08T11:18:51Z")
**Posts on this page:** 1
**Showing post:** 132
### Author:  [@Scrumplex](https://discourse.nixos.org/u/Scrumplex)
#### Post date: [April 27, 2026, 6:27am UTC](https://discourse.nixos.org/t/breaking-changes-announcement-for-unstable/17574/132 "2026-04-27T06:27:19Z")
`fetcherVersion = 1` of `fetchPnpmDeps` has been deprecated and scheduled for removal in 26.11:
>
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> Depends on #513204. Please review diff with whitespaces off.
>
> \`fetcherVersion = …1\` was kept around for backwards compatibility while callers migrated to \`2\`/\`3\`. With #494402 merged, only #513204 remains on master.
>
> This PR emits a \`lib.warnIf\` warning whenever \`fetchPnpmDeps\` is called with \`fetcherVersion = 1\`, giving callers advance notice before the planned removal in 26.11. Per @Scrumplex's review the warning fires immediately on merge rather than being gated by \`lib.oldestSupportedReleaseIsAtLeast\`, since 26.05 will not include any packages with \`fetcherVersion = 1\` once #513204 lands.
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> After 26.11 ships, a follow-up PR should drop \`1\` from \`supportedFetcherVersions\` and clean up the dead v1 branches in \`default.nix\`, \`pnpm-config-hook.sh\`, and \`serve.nix\`.
>
> \## Things done
> \- \[x\] Fits \[CONTRIBUTING.md\](https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md), \[pkgs/README.md\](https://github.com/NixOS/nixpkgs/blob/master/pkgs/README.md), \[maintainers/README.md\](https://github.com/NixOS/nixpkgs/blob/master/maintainers/README.md) and other READMEs.
> \- Nixpkgs Release Notes
> - \[x\] Package update: when the change is major or breaking.
All packages in nixpkgs have been migrated to version 3. A warning is now emitted if `fetcherVersion = 1` is used.
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_[View the full topic](https://discourse.nixos.org/t/breaking-changes-announcement-for-unstable/17574)._