You can find the installed version of a package with
dpkg -l [package name], or just search on the Internet for the package name along with "Raspbian Stretch"; you'll usually find packages.debian.org pretty high in the results which tells you the version available in the repository.
For Stretch, the available package is
1.4.0-0.1+b1, which is far more recent than the version mentioned in the thread you linked,
0.13.4-beta (which is to be expected, as that issue was posted in 2007, and it's been 11 years since that page was updated!).
That said, there is a "new" release of gputils, according to the project website; version 1.5.0 was released in August 2016. Curiously it appears no-one has bothered to package the latest version, but I doubt you'd need to update anyway, as your version is already much newer than the one listed in the linked thread.
If you're experiencing a similar error message, it may not be the same issue; it may be worth posting a new issue on their bug tracker, or perhaps asking here if relevant with the error message you get.