These errors may be seen in the Nios® II Software Build Tools for Eclipse version 9.1 because it stores metadata in the workspace. Therefore it will cause a variety of problems if you attempt to work with projects located in the workspace. Depending on what you are attempting to do, there may be no warning issued by the software tool.
Here is an example of the error you will see if you try to recreate a project in Eclipse's workspace after previously deleting the same named project, also in the Eclipse workspace:
"Unable to create project. Reason: Unable to create project in workspace directory".
In order to workaround these issues, create a new workspace separate from your project files. This can be done as follows:
- From the menu, "File->switch workspace".
- Create a new workspace for dedicated internal use by Nios II SBT for Eclipse by clicking on "Other...".
This workspace should contain no other files than the .metadata created by the Nios II SBT for Eclipse.
This issue is currently scheduled to be fixed in a future release of the Nios II SBT for Eclipse.