Freshly downloaded Eclipse 4.3 for java EE, with an empty workspace.
Trying to install spoofax, but it cannot be completed due to the following error.

Cannot complete the install because one or more required items could not be found.   Software being installed: Spoofax/IMP 1.1.0.0-r26055 (org.strategoxt.imp.feature.group 1.1.0.0-r26055)   Missing requirement: Spoofax/IMP 1.1.0.0-r26055 (org.strategoxt.imp.feature.group 1.1.0.0-r26055) requires 'org.junit4 0.0.0' but it could not be found

I have checked contact all software sites during ...

Also happens with nightly.

Submitted by Elmer van Chastelet on 30 June 2013 at 13:00

Please update dependency in manifest to org.junit instead of org.junit4.
search org.junit4 on github metaborg repos

See https://bugs.eclipse.org/bugs/show_bug.cgi?id=401716

Fixed for both nightly and stable. Thanks for your helpful description!

I got this for a fresh Eclipse download, for the stable update site.

It was fixed in nightly, not stable. If you want to fix it in stable, merge the fix into the spoofax-release branch and make a new release.

Edit: the fix might already be merged into stable, but no new release was made

The fix is indeed in stable code (since 2010). The stable update site (http://download.spoofax.org/update/stable) is static. I have just uploaded a new build corresponding to the latest build from hydra to the stable update site. It installs in Kepler without problems.