30 minutes won't be enough to solve many nasty bugs, but it can be enough time to rule out a possible cause, or rule out a possible technique as not being helpful for tracking the bug down.
One of my nastier crashes took two weeks to root cause - I eventually ruled out every smart technique I could think of, and resorted to dumb ones. 15 or so build + test cycles later (taking maybe 10 minutes of work each and another 2 hours of waiting for builds to complete) I'd bisected VCS history and found the cause. Turned out to be a change to use some third party code that looked completely unrelated. So unrelated that I spent another 10 minutes creating a completely isolated standalone repro case to verify I'd actually found the culprit (I had) instead of something that would hide the symptoms.
30 minutes won't be enough to solve many nasty bugs, but it can be enough time to rule out a possible cause, or rule out a possible technique as not being helpful for tracking the bug down.
One of my nastier crashes took two weeks to root cause - I eventually ruled out every smart technique I could think of, and resorted to dumb ones. 15 or so build + test cycles later (taking maybe 10 minutes of work each and another 2 hours of waiting for builds to complete) I'd bisected VCS history and found the cause. Turned out to be a change to use some third party code that looked completely unrelated. So unrelated that I spent another 10 minutes creating a completely isolated standalone repro case to verify I'd actually found the culprit (I had) instead of something that would hide the symptoms.