Comment 7 for bug 1690519

Checked "man malloc" once again, there I find:

> The following environment variables change the behavior of the allocation-related functions.

I will try these first:
MallocGuardEdges=y, MallocStackLoggingNoCompact=y, MallocScribble=y,
MallocCheckHeapStart=20000, MallocCheckHeapEach=100, MallocCheckHeapSleep=1200

See also "leaks" (XCode tool), malloc_history.

gnu/Ubuntu should have similar tools.