Originally Posted by ZacWolf
Yes, I moved "My Documents" from the default /Users location to another drive with Raid5, via the Move Folder [Special Folders] option.
This could possibly be the issue then. I've changed the location of Sigil's temp folder from "<HomePath>/My Documents/Sigil" to "<HomePath>/Sigil", but after 0.1.8 was released.
Now do try building from source, but from the repository, not the prepackaged source archive.