[Thread 5] pl-index.c:811: cleanClauseIndex: Assertion failed: (INT)ci->size >= 0
C-stack trace labeled "crash":
  [0] save_backtrace() AT :? [0x7f9921966630]
  [1] __assert_fail() AT ??:? [0x7f992192bb21]
  [2] cleanClauseIndexes() AT :? [0x7f99218b49e3]
  [3] cleanDefinition.part.11() AT pl-proc.c:? [0x7f9921900501]
  [4] gcClausesDefinitionAndUnlock() AT :? [0x7f9921902477]
  [5] pl_clauseva_va() AT pl-comp.c:? [0x7f99218e38ed]
% GC: gained 498,800+27,640 in 0.00 sec; used 21,304+616; free 502,968+261,520
  [6] PL_next_solution() AT ??:? [0x7f99218c2658]
  [7] callProlog() AT :? [0x7f99218ffc03]
  [8] start_thread() AT pl-thread.c:? [0x7f99219318fe]
  [9] start_thread() AT /build/buildd/eglibc-2.19/nptl/pthread_create.c:312 (discriminator 2) [0x7f9921679182]
  [10] clone() AT /build/buildd/eglibc-2.19/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:113 [0x7f99213a647d]
prologmud@ubuntu:/opt/PrologMUD$


?- % Started AT Mon Aug  3 12:21:39 2015
% 280.678 seconds cpu time FOR 458,954,248 inferences
% 991,268 atoms, 23,202 functors, 21,194 predicates, 222 modules, 270,858,630 VM-codes
%
%                        Limit    Allocated       In use
% Local  stack: 64,000,004,096      126,976       23,424 Bytes
% Global stack: 64,000,004,096      258,032       79,728 Bytes
% Trail  stack: 64,000,002,048      129,016        2,488 Bytes
%
% 7,334 garbage collections gained 917,645,968 bytes in 1.533 seconds.
% 129 atom garbage collections gained 1,243,353 atoms in 4.772 seconds.
% Stack shifts: 11 local, 8 global, 5 trail in 0.003 seconds
% 8 threads, 0 finished threads used 0.000 seconds
true.