Beginning with nightly 20140501, an updated recovery that has kernel support for by-name partitions is required to install/update CyanogenMod on certain devices.
The following devices are affected:
evita – HTC One XL
fireball – HTC Droid Incredible 4G LTE
jewel – HTC EVO 4G LTE
m4 – HTC One Mini
m7 – HTC One [GSM]
m7spr – HTC One [Sprint]
m7vzw – HTC One [Verizon]
ville – HTC One S
For more info (and steps) see our wiki: http://wiki.cyanogenmod.org/w/HTC_fstab_updates