I want to read ESRI ASCII geo grid files into java. Therefore geotools and t-arcgrid are required.

When loading these into set like

libraryDependencies ++= Seq(
  "org.geotools" % "gt-main" % geotools,
  "org.geotools" % "gt-arcgrid" % geotools
)

I get unresolved dependency: it.geosolutions.jaiext.even though additional resolvers were added:

resolvers += "osgeo" at "http://download.osgeo.org/webdav/geotools"
resolvers += "boundless" at "http://repo.boundlessgeo.com/main"

It should reside in the boundless repository, but is not resolved http://mvnrepository.com/artifact/it.geosolutions.jaiext/jaiext/1.1.8

When checking the logs http://repo.boundlessgeo.com/main/it/geosolutions/imageio-ext/imageio-ext-arcgrid/1.1.17/imageio-ext-arcgrid-1.1.17.pom is trying to be accessed. If I click in the browser an imageio-ext-arcgrid-1.1.17.pom is downloaded. What is wrong here with SBT? The same problem can be observed for several (transitive) dependencies.

To reproduce the example here is a minimal git project as well https://github.com/geoHeil/geoToolsProblem, but all the relevant code is already present above.

edit

Appending "org.geotools" % "gt-coverage" % geotools, to the dependencies won't help.

It looks like adding resolvers += "imageio" at "http://maven.geo-solutions.it" will make it work.