Memory Leak detection in Lazarus - again

Question

I am using Lazarus 2.0.4 on Windows 10.

Trying to track memory leaks in a quite large project I tried to familiarize myself with the heaptrc and lineinfo units/compiler switches -gh and -gl.

While this gives me some information that there is a leak somewhere, I could not figure out how to pinpoint the exact location. I put together this quite basic leaking code which will leak 4 bytes every time the button is pressed. Upon exit of the program I get this:

While from the trace I see that there is a 4 byte memory leak, I cannot see any useful reference where to look for the leaking code. I see that the code was within the click handler of a TButton, but this isn't very useful, since there may be many Buttons.

Any way to get a reference to the exact location (line 42)?