"I can't hack this heat!"
"What are you doing?"
"I'm hacking TECO."
In a general (time-extended) sense:
"What do you do around here?"
"I hack TECO."
More generally, "I hack 'foo'" is roughly equivalent to "'foo' is my major interest (or project)".
"I hack solid-state physics."
See sense 2 and hacker (sense 5).
"Whatcha up to?"
"Oh, just hacking."
Constructions on this term abound. They include 'happy hacking' (a farewell), 'how's hacking?' (a friendly greeting among hackers) and 'hack, hack' (a fairly content-free but friendly comment, often used as a temporary farewell).