The latest graph-tool 2.32 was not built for 19.04 because it has been
discontinued (reached end of life). Maybe the error above is because you
installed a package for another ubuntu version?


Thanks Tiago. It is true that 19.04 is dead, but somehow when I installed graph-tool, it did show me version 2.32 got installed (on the terminal verbose). I will upgrade to a stable Ubuntu version, and will give another try. Thanks so much for your time.

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