Gradle builds are fast because Gradle supports incremental tasks. This means Gradle can determine if input or output of task has changed, before running the task. If nothing has changed a task is marked a up-to-date and the task is not executed, otherwise the task is executed. If we want execute a task even if it is up-to-date we must use the command line option --rerun-tasks.

In the following example we run the assemble task for a simple Java project, and we see all tasks are executed. When we invoke the assemble task again we see the tasks are all up-to-date:

$ gradle assemble

:compileJava
:processResources
:classes
:jar
:assemble

BUILD SUCCESSFUL

Total time: 1.765 secs
$ gradle assemble

:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:jar UP-TO-DATE
:assemble UP-TO-DATE

BUILD SUCCESSFUL

Total time: 0.715 secs
$

To run all tasks without an up-to-date check we use the option --rerun-tasks:

$ gradle --rerun-tasks assemble
:compileJava
:processResources
:classes
:jar
:assemble

BUILD SUCCESSFUL

Total time: 1.037 secs
$

Written with Gradle 3.2.1.

shadow-left