[FLASH-USERS] SIGSEGV 174 error in Flash 4.5

[Klaus Weide]

On Mon, 18 Mar 2019, Plechaty, Christopher wrote:

> I searched other posts I found some issues with guard cells in Flash 4.3 that were solved utilizing the –O0 optimization flag. Unfortunately, that does not work here. Has anyone seen this error before? 
> 
>  
> 
> Error:
> 
> flash4debug        0000000000E4EA7D  Unknown               Unknown  Unknown
> 
> libpthread-2.17.s  00002AF5FDEFC6D0  Unknown               Unknown  Unknown

I notice that in both traces you have sent, the 2nd line has 
libpthread-2.17.s .

> flash4debug        00000000004CCF2B  amr_1blk_cc_cp_re         355  amr_1blk_cc_cp_remote.F90

In this case, line number 355 points to the statement

              unk1(ivar_next,ii,jj,kk,idest) =                         &
                       temprecv_buf(indx+ivar)

which is part of a loop nest that copies a potentially large amount of 
data from a receive-buffer.

It is possible that
 * your compiler is trying to optimize the data-copying by automatically
   using threads;
 * something goes wrong with this (occasionally); and
 * you can find some way (compiler flag, maybe env variable) to turn off 
   this behavior (even of -O0 alone does not do that), or maybe use a
   different compiler version or configuration.

Klaus