How to resolve artifact without extension?

I have artifact that has no extension (linux libraries) in ARM, but Icannot resolve them in ivy.xml it is described: … …

gradle script dependencies are: compile(group: ‘group-name’, name: ‘art_name’, version: ‘1.1.1’, classifier: ‘linux_x86’)

but when execute gradle script it gives following error

A problem occurred evaluating root project ‘test’. > Could not resolve all dependencies for configuration ‘:compile’.

Artifact ‘group-name:art_name:1.1.1:linux_x86@jar’ not found.

It takes by default ext: jar I have also tried to specify extension compile(group: ‘group-name’, name: ‘art_name’, version: ‘1.1.1’, classifier: ‘linux_x86’, ext: ‘’)

But again same error is produced: A problem occurred evaluating root project ‘test’. > Could not resolve all dependencies for configuration ‘:compile’.

Artifact ‘group-name:art_name:1.1.1:linux_x86@jar’ not found.