Explicit error message for SSSP run over a graph with no edge weight

[yecol]

• Or support by treating the edge weight as 1 equally.

Discussed in #1637

^{Originally posted by FishieJ May 27, 2022}
I'm trying to run graphscope.sssp in Jupyter notebook and encounted the following error:

CompilationError: Failed to compile app grape::SSSP<_GRAPH_TYPE> on platform system: Darwin
machine: x86_64
platform: macOS-11.5.2-x86_64-i386-64bit
uname: uname_result(system='Darwin', node='zhangsan.local', release='20.6.0', version='Darwin Kernel Version 20.6.0: Wed Jun 23 00:26:31 PDT 2021; root:xnu-7195.141.2~5/RELEASE_X86_64', machine='x86_64')
kernel_ver: Darwin Kernel Version 20.6.0: Wed Jun 23 00:26:31 PDT 2021; root:xnu-7195.141.2~5/RELEASE_X86_64
mac_ver: ('11.5.2', ('', '', ''), 'x86_64')
gcc_ver: b'gcc (Homebrew GCC 11.1.0) 11.1.0\nCopyright (C) 2021 Free Software Foundation, Inc.\nThis is free software; see the source for copying conditions. There is NO\nwarranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n'
python_ver: 3.9.13

According to the above printed info (including mac_ver, gcc_ver, python_ver), I think I have satisfied all prequisites of installation. graphscope.__version__ is '0.13.0'.

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Having tried gcc ver 7.3 in vain. It seems like graphscope still uses MacOS's default clang when compiling sssp.