x/exp/cmd/gorelease: diagnostic about proposed prerelease

Adds diagnostics about:

- Prereleases with suffixes that sort lower than pseudo-versions.
- Prereleases with plus signs.

Fixes golang/go#37565

Change-Id: I210df3a0c37912963e750c632d1dc4a556e94e88
Reviewed-on: https://go-review.googlesource.com/c/exp/+/257077
Trust: Jean de Klerk <deklerk@google.com>
Trust: Jay Conrod <jayconrod@google.com>
Run-TryBot: Jean de Klerk <deklerk@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
9 files changed
tree: c74e36a69678ad493b3c6c397d976041e507420b
  1. apidiff/
  2. cmd/
  3. ebnf/
  4. ebnflint/
  5. errors/
  6. fsnotify/
  7. inotify/
  8. io/
  9. mmap/
  10. rand/
  11. shiny/
  12. shootout/
  13. sumdb/
  14. utf8string/
  15. winfsnotify/
  16. .gitattributes
  17. .gitignore
  18. AUTHORS
  19. codereview.cfg
  20. CONTRIBUTING.md
  21. CONTRIBUTORS
  22. go.mod
  23. go.sum
  24. LICENSE
  25. PATENTS
  26. README.md
README.md

exp

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.