llvm dev - Aug 2018 - opt error with -early-cse-memssa option

Hi all,
I get an error when I use opt with -early-cse-memssa option.
I randomly generate some pass sequences and I find the sequences
"-early-cse-memssa -lcssa-verification -early-cse-memssa",
"-early-cse-memssa -verify -early-cse-memssa", "-early-cse-memssa
-demanded-bits -early-cse-memssa" and "-early-cse-memssa
-early-cse-memssa"
will cause the following error for LLVM version 6.0.0.


LLVMSymbolizer: error reading file: No such file or directory
#0 0x0000000001a68794 (opt+0x1a68794)
#1 0x0000000001a68a76 (opt+0x1a68a76)
#2 0x00007f96a098c390 __restore_rt
(/lib/x86_64-linux-gnu/libpthread.so.0+0x11390)
#3 0x00000000015fc64e (opt+0x15fc64e)
#4 0x000000000160065d (opt+0x160065d)
#5 0x00000000015fdb08 (opt+0x15fdb08)
#6 0x000000000075aaa6 (opt+0x75aaa6)
#7 0x00007f969f924830 __libc_start_main
(/lib/x86_64-linux-gnu/libc.so.6+0x20830)
#8 0x000000000074c1b9 (opt+0x74c1b9)
Stack dump:
0.      Program arguments: opt -early-cse-memssa -lcssa-verification
-early-cse-memssa matrix.bc -o matrix-opt.bc
Segmentation fault (core dumped)


I also try the following commond
    llvm-as < /dev/null | opt -early-cse-memssa -lcssa-verification
-early-cse-memssa, (the same to other sequences)
which also gets the same error. So this error is not sensitive to input.


Is it a bug for LLVM/opt? Or I make a mistake to use this pass option or opt?
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