Truck will bump start but won't jump start?

My 95 GMC S15 pickup won't start. Battery is less than 2 yrs and has good voltage reading, starter is less than 1 yr and have had it tested, alternator should be okay because lights and stereo come on, truck will bump start but won't jump start. This problem came on gradually over about 6 months, occasionally it wouldn't start until turning key 4 or 5 times, now it won't start without popping clutch. I think it's an ignition system problem?