before detach:  173693530 (0x0a5a5a5a)
after detach:   0 (0x00000000)
after spray:    -559038737 (0xffffffffdeadbeef)
df4773: spray: 8 chunks reclaimed with 0xdeadbeef
df4773: unload: oid removal happens NOW M-bM^@M^T after backing free (the DF-4773 window)
malloc_uninit: 64 bytes of 'df4773' still allocated on cpu 6