./grmerge -e 0 -cp 1 demo-a.grl demo-b.grl output about graphlib@3.0.0 on centos_aarch64

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hello,I meet a problem:./grmerge -e 0 -cp 1 demo-a.grl demo-b.grl output about graphlib@3.0.0 on centos_aarch64
### Steps to reproduce the issue

```console
[root@localhost spack-build-35uytdz]# ls
CMakeCache.txt Makefile demo-a.dot demo-a.pdot demo-b.grl demo-d.dot demo-f-1.gml demo-f.grl demo-g1.dot demo-g3.dot graphdemo grmerge liblnlgraph.so
CMakeFiles cmake_install.cmake demo-a.grl demo-b.dot demo-c.grl demo-e.dot demo-f-2.gml demo-g.grl demo-g2.dot demo-g4.dot graphlib-config.cmake install_manifest.txt
[root@localhost spack-build-35uytdz]# ./grmerge -h
Graphlib-Merge Utility, Martin Schulz, LLNL, 2005
Usage: grmerge [-e ] [-cp ] infile1 [infile2 ... ] outfile
Format can be: 0 = DOT
1 = GML
Stage flags can be: 1 = Prune tree
2 = Scale nodes
4 = Collapse chains
[root@localhost spack-build-35uytdz]# ./grmerge -e 0 -cp 1 demo-a.grl demo-b.grl output
Graphlib-Merge Utility, Martin Schulz, LLNL, 2005
Loading demo-a.grl
Segmentation fault (core dumped)
```
Can you tell me why it causes such a problem?

Start by reproducing the command `./grmerge -e 0 -cp 1 demo-a.grl demo-b.grl output` with the supplied `demo-a.grl` input and inspect the crash in grmerge. Determine why loading `demo-a.grl` segfaults on centos_aarch64, then verify that the command completes without a segmentation fault.

Written by the indexing model from the issue text.