Created attachment 866285 [details] screencast of the bug Attaching a screencast and logs. Booting a recent Rawhide nightly on a VM with an installed Fedora. Go to custom partitioning. The existing install is correctly displayed. Try to delete one of its partitions. It is correctly removed from the treeview, but the 'available space' calculation does not change. Attempting to create new partitions fails (even though the removed partition should have freed up sufficient space for this). After the attempt, the 'removed' partition is showing up in the treeview again. This is reliably and repeatably reproducible.
Created attachment 866286 [details] storage.log from a reproduction of the bug
Created attachment 866287 [details] anaconda.log from a reproduction of the bug
Created attachment 866288 [details] program.log from a reproduction of the bug
Proposing as a Beta blocker: "When using the custom partitioning flow, the installer must be able to: ... Remove existing storage volumes" https://fedoraproject.org/wiki/Fedora_20_Beta_Release_Criteria#Custom_partitioning
d'oh. notabug. it was an LV, not a partition.