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# Migrating to 25.04

[Nextflow 25.04](https://github.com/nextflow-io/nextflow/releases/tag/v25.04.0) was released on May 8, 2025.

## New features

<h3>Strict syntax</h3>

The *strict syntax* is a strict parser for Nextflow DSL2 that implements the {ref}`Nextflow language specification <syntax-page>`. Originally introduced by the [Nextflow language server](https://github.com/nextflow-io/language-server) alongside Nextflow 24.10, the strict syntax is now available in the Nextflow CLI.

The strict syntax is disabled by default. Enable it by setting the environment variable `NXF_SYNTAX_PARSER=v2`. See {ref}`strict-syntax-page` for details.

<h3>Linting and formatting</h3>

The `nextflow lint` command checks Nextflow scripts and config files for errors using the {ref}`strict syntax <strict-syntax-page>`. It can also format Nextflow files using the same formatter as the Nextflow language server. See {ref}`cli-lint` for details.

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<h3>Workflow outputs (third preview)</h3>

The third preview of workflow outputs introduces the following breaking changes from the {ref}`previous version <workflow-outputs-second-preview>`:

- The `publish:` section can only be specified in the entry workflow.

- Workflow outputs in the `publish:` section are assigned instead of using the `>>` operator. Output names must be valid identifiers.

- By default, output files are published to the base output directory, rather than a subdirectory corresponding to the output name.

- The syntax for dynamic publish paths has changed. Instead of defining a closure that returns a closure with the `path` directive, the outer closure should use the `>>` operator to publish individual files. See {ref}`workflow-publishing-files` for details.

- The `mapper` index directive has been removed. Use a `map` operator in the workflow body instead.

See {ref}`migrating-workflow-outputs` to get started.

<h3>Topic channels (out of preview)</h3>

{ref}`Topic channels <channel-topic>`, introduced in Nextflow 24.04 as a preview feature, have been brought out of preview, which means that they can be used without the `nextflow.preview.topic` feature flag.

<h3>Data lineage</h3>

This release introduces built-in provenance tracking, also known as *data lineage*. When `lineage.enabled` is set to `true` in your configuration, Nextflow will record every workflow run, task execution, output file, and the links between them.

You can explore this lineage from the command line using the {ref}`cli-lineage` command. Additionally, you can refer to files in the lineage store from a Nextflow script using the `lid://` path prefix as well as the {ref}`channel-from-lineage` channel factory.

See {ref}`data-lineage-page` to get started.

<h3>Simplified plugin development</h3>

The `nextflow plugin create` sub-command creates the scaffold for a Nextflow plugin using the official [Nextflow plugin template](https://github.com/nextflow-io/nf-plugin-template/). It is simpler and easier to maintain than the previous plugin boilerplate.

See the {ref}`gradle-plugin-page` guide for details.

## Enhancements

<h3>Improved <code>inspect</code> command</h3>

Previously, the `nextflow inspect` command included all processes that were invoked in a preview run. Now, the `inspect` command includes all processes that are *included* by the entry workflow (directly or indirectly), which has several benefits:

- It includes all processes that could potentially be invoked by the workflow, not just the processes that are invoked for a particular run configuration.

- It's faster, as it doesn't need to evaluate the entry workflow -- only the includes.

- It can be run as `nextflow inspect <PIPELINE>`, without specifying any parameters or config profiles.

See {ref}`cli-inspect` to learn more about the `inspect` command.

<h3>Plugin version ranges</h3>

When specifying a plugin, the plugin version can now be prefixed with `~` to pin the major and minor version while allowing the latest patch release. This syntax makes it possible to pin the plugin version while automatically using new patch releases.

See {ref}`plugins-page` for details.

<h3>Improved publish error handling</h3>

Nextflow will terminate the run if the thread pool responsible for publishing files takes too long. Previously, this timeout was reported as a warning. Now, it is reported as an error.

The previous behavior can be restored with the following config setting:

```groovy
workflow.output.ignoreErrors = true
```

## Breaking changes

- Nextflow now requires Java 17 or newer. See {ref}`install-requirements` for instructions to install Java 17.

- The {ref}`hyperqueue-executor` executor now requires HyperQueue 0.20.0 or later.

## Deprecations

- The process `shell` section has been deprecated. See {ref}`process-shell` for details.

- Nextflow will report a warning if it encounters a process `shell` directive that contains newlines. This warning will become an error in a future release.

- The `-with-weblog` CLI option has been deprecated. See [nextflow-io/nf-weblog](https://github.com/nextflow-io/nf-weblog) to learn how to use the `nf-weblog` plugin.

## Miscellaneous

- New config option: `aws.batch.terminateUnschedulableJobs`
- New config option: `azure.batch.jobMaxWallClockTime`
- New config option: `fusion.snapshots`
- New config option: `google.batch.gcsfuseOptions`
- New config option: `google.batch.networkTags`
- New config option: `workflow.output.copyAttributes`
- New environment variable: `NXF_PLUGINS_ALLOWED`
- New plugin extension point: `TraceObserverFactoryV2`
- New standard library function: `env()`
- Support `disk` directive for Azure Batch