Can not build go-imap/imap on Go1.0.3

[c9s]

Got errors below:

go build
_/Users/c9s/src/go/go-imap/imap
./imap.go:11: undefined: os.Error
./imap.go:39: undefined: os.Error
./imap.go:61: undefined: os.Error
./imap.go:78: undefined: os.Error
./imap.go:109: undefined: os.Error
./imap.go:134: undefined: os.Error
./imap.go:163: undefined: os.Error
./imap.go:210: undefined: os.Error
./imap.go:227: undefined: os.Error
./imap.go:255: undefined: os.Error
./imap.go:255: too many errors