In D11973#228622, @vtorri wrote:

@bu5hm4n wait a bit : it seems that mallinfo in libmalloc should not be used, i am waiting some confirmation

Thank you Vincent, for reference error strings on illumos are listed at http://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libc/port/gen/errlist , see enum value 12 for ENOMEM.