(config-feature-flags)=
Feature flags enable opt-in features. They must be specified in the pipeline script.
:::{warning}
Feature flags marked as preview can cause pipelines run with newer versions of Nextflow to fail due to breaking changes. Always consult the {ref}migration notes <migrations-page> before updating to a new Nextflow version.
:::
nextflow.enable.configProcessNamesValidation
: :::{deprecated} 25.10.0
Use the {ref}strict syntax <strict-syntax-page> instead. It validates process selectors without producing false warnings.
:::
: When true, prints a warning for every withName: process selector that doesn't match a process in the pipeline (default: true).
nextflow.enable.dsl
: :::{deprecated} 25.04.0
:::
: Defines the DSL version to use (1 or 2).
nextflow.enable.moduleBinaries
: When true, enables the use of module-scoped executable scripts via {ref}module resources <module-resources>.
nextflow.enable.strict
: :::{deprecated} 26.04.0
:::
: When true, executes the pipeline in "strict" mode, which introduces the following rules:
-
When reading a params file, Nextflow will fail if a dynamic param value references an undefined variable
-
When merging params from a config file with params from the command line, Nextflow will fail if a param is specified from both sources but with different types
-
When using the
joinoperator, thefailOnDuplicateoption istrueregardless of any user setting -
When using the
joinoperator, thefailOnMismatchoption istrue(unlessremainderis alsotrue) regardless of any user setting -
When using the
publishDirprocess directive, thefailOnErroroption istrueregardless of any user setting -
In a process definition, Nextflow will fail if an input or output tuple has only one element
-
In a process definition, Nextflow will fail if an output emit name is not a valid identifier (i.e. it should match the pattern
/[A-Za-z_][A-Za-z0-9_]*/) -
During a process execution, Nextflow will fail if a received input tuple does not have the same number of elements as was declared
-
During a process execution, Nextflow will fail if the
storeDirdirective is used with non-file outputs -
Nextflow will fail if a pipeline param is referenced before it is defined
-
Nextflow will fail if multiple functions and/or processes with the same name are defined in a module script
nextflow.enable.types
: :::{versionadded} 26.04.0
:::
: Preview feature: the syntax and behavior may change in future releases.
: When true, enables the use of {ref}typed processes <process-typed-page> and {ref}typed workflows <workflow-typed-page>. Must be enabled in every script that uses typed processes/workflows. Legacy processes/workflows cannot be defined in scripts with this flag enabled.