Composer is good when it works, but when it stops is a real PITA to understand what is going on. Sometimes cleaning a project helps, sometimes, re-importing does the magic, but sometimes nothing works. Almost.
So I had this issue that a perfectly fine Composer project one day simply stopped building. At all. All I was getting was this error message:
'Dar Install Options Set' of 'Dar Def-Methods' must be set default.dardef /Methods/dar org.eclipse.emf.ecore Problem
Turned out that project settings (upgrade/overwrite etc.) *somehow* vanished from default.dardef file, so I have added it back:
<darInstallOptionsSet> <location xsi:type="installparameter:FolderParameter" href="urn:com.emc.ide.folderparameter/Dar+Install+Folder?artifactURI=file:/C:/Composer/Methods/Artifacts/Installation%20Parameters/darinstallfolder.parameter#//@dataModel"/> <upgradeOption xsi:type="dardef:UpgradeOption"/> </darInstallOptionsSet>
And it started working fine again…