https://docs.inedo.com/docs/proget/api/pgutil#sources :
~/pgutil/pgutil.config is incorrect for Ubuntu 24.04.4 which actually puts it in ~/.config/pgutil/pgutil.config

+ pgutil upack install --source=$SOURCE --package=$NAME1/$NAME2 --version=26.3 --feed=$FEED --target=instdir/
Unhandled exception. System.ArgumentException: String is not a valid semantic version.
   at Inedo.ProGet.UniversalPackages.UniversalPackageVersion.Parse(String s)
   at PgUtil.Program.UpackCommand.GetPackageAsync(CommandContext context, CancellationToken cancellationToken)
   at PgUtil.Program.UpackCommand.InstallCommand.ExecuteAsync(CommandContext context, CancellationToken cancellationToken)
   at ConsoleMan.Command.ExecuteAsync(String[] args)
   at PgUtil.Program.Main(String[] args)
   at PgUtil.Program.<Main>(String[] args)
./sdk_proget_put.sh: line 84: 410933 Aborted                 (core dumped) pgutil upack install --source=$SOURCE --package=$NAME1/$NAME2 --version=$SEMVER --feed=$FEED --target=$TARGETDIR/

The core dump does not occur when version is changed from 26.3 to 26.3.0. I am reporting the fact that pgutil core dumps on invalid version input.