I’m not seeing pkgman expose that information anywhere. If anyone has a secret parameter, let me know.
While we’re on the subject, pkgman search really could use a -b option. B for bare, where it just gives the package names with no flags, no short descriptions, no padding. Like ls -b -1.
Was looking for that information earlier also without finding it, maybe @BiPolar can help out here, he’s the pkgman guru 
You can get just the names by running the output of pkgman search through something like cut -c -40, but it doesn’t trim the blanks. However using awk ‘{print $1}’ as a filter works perfectly.