I ran into what I think is a bug today. Basically I prepared a spell from a rune, tried to cast it but received the research interuption warning but It consumed my held mana and use up the spell in spite of the spell not taking effect. Here is an edited log:

>>>Look
You also see some crushed ojhenik, some crushed ojhenik, some crushed ojhenik, an ornery Shadow Servant, an open crate, a stone pile, the Sur'oson Gate and a large stable built against the city wall.

>>>Focus Rune
You focus your magical senses on a dark asketine runestone.
You recognize the pattern of the Compost spell.
You should get three more spells out of the runestone before it wears out.

>>>invoke rune
The saturated tunnels in the runestone form the foundation of a spell pattern. With this template in place, you begin preparing the Compost spell.
That will disrupt less than a quarter of your current attunement.

>>>Power
You are preparing the Compost spell at twenty mana.

>>>harn 10
You tap into the mana from ten of the surrounding streams and attempt to keep it channeling in a stream around you.

You feel fully prepared to cast your spell.

>>>cast
You gesture.
You contribute your harnessed streams to increase the pattern's potential.
Are you sure you want to do that? You'll interrupt your research!
[Enter your command again if you want to.]
Emotional pain and exhaustion lingers in your mind, even after you regain rational control.

>>>cast
You don't have a spell prepared!

>>>Look
You also see some crushed ojhenik, some crushed ojhenik, some crushed ojhenik, an ornery Shadow Servant, an open crate, a stone pile, the Sur'oson Gate and a large stable built against the city wall.