mount points preparation locked - "No root file system"
Ubiquity's advanced partitioner in Edgy cannot reuse an existing partition as the root file system, and will incorrectly claim "No root file system". Deleting and re-creating the partition in question in the advanced partitioner is a workaround (since you must reformat the partition anyway), but this is very confusing and causes many failed installations.
This bug was introduced due to an attempt to fix handling of HFS bootstrap partitions, and was corrected in ubiquity 1.3.0 in Feisty; I have not heard of any regressions due to this fix. The validation code did not take account of the fact that the 'fstype' variable is set to None for pre-existing partitions as well as for special-purpose partitions such as HFS bootstrap partitions.
A proposed patch for edgy is attached (http://