Segfault in parallel gb calls

I keep running into this segfault when running parallel threads. I don't get the same segfault in sequential computation.

 0# std::vector<boost::stacktrace::frame, std::allocator<boost::stacktrace::frame> >::size() const at /usr/lib/gcc/x86_64-pc-linux-gnu/12/include/g++-v12/bits/stl_vector.h:988
 1# segv_handler at /home/mahrud/scratch/M2/M2/Macaulay2/bin/main.cpp:247
 2# 0x0000152CEA663790 in /usr/lib64/libc.so.6
 3# gbA::auto_reduce_by(int) at /home/mahrud/scratch/M2/M2/Macaulay2/e/gb-default.cpp:2072
 4# gbA::insert_gb(POLY, int) at /home/mahrud/scratch/M2/M2/Macaulay2/e/gb-default.cpp:2193 (discriminator 1)
 5# gbA::process_spair(gbA::spair*) at /home/mahrud/scratch/M2/M2/Macaulay2/e/gb-default.cpp:2316
 6# gbA::do_computation() at /home/mahrud/scratch/M2/M2/Macaulay2/e/gb-default.cpp:2523
 7# gbA::start_computation() at /home/mahrud/scratch/M2/M2/Macaulay2/e/gb-default.cpp:2596
 8# Computation::status() const at /home/mahrud/scratch/M2/M2/Macaulay2/e/comp.hpp:49
 9# rawStartComputation at /home/mahrud/scratch/M2/M2/Macaulay2/e/interface/groebner.cpp:272
10# interface_rawStartComputation at /home/mahrud/scratch/M2/M2/Macaulay2/d/interface.dd:3391

cc: @mikestillman @jkyang92

Start by reproducing the crash in parallel and sequential computation, then inspect e/gb-default.cpp around auto_reduce_by, insert_gb, process_spair, and do_computation using the provided stack trace. Trace the parallel execution path from e/interface/groebner.cpp and confirm that the computation completes without a segmentation fault.