golang-golang-x-exp-dev binary package in Ubuntu Lunar amd64

 This subrepository holds experimental and deprecated (in the "old" directory)
 packages.
 .
 The idea for this subrepository originated as the "pkg/exp" directory of the
 main repository, but its presence there made it unavailable to users of the
 binary downloads of the Go installation. The subrepository has therefore been
 created to make it possible to "go get" these packages.
 .
 Warning: Packages here are experimental and unreliable. Some may one day be
 promoted to the main repository or other subrepository, or they may be modified
 arbitrarily or even disappear altogether.
 .
 In short, code in this subrepository is not subject to the Go 1 compatibility
 promise. (No subrepo is, but the promise is even more likely to be violated by
 go.exp than the others.)
 .
 Caveat emptor.

Source package