x/exp/cmd/gorelease: err when main module requests lower version than cycle

When there is a cycle like,

main@v1.0.0 -> foo@v1.0.0
foo@v1.0.0 -> main@v1.5.0

And the user suggests main@v1.1.1 (or anything <= 1.5.0), report an error, since
MVS will never choose that version.

Fixes golang/go#37567

Change-Id: I95628c49e0949116ec8019364f5c760dcc7c80a3
Reviewed-on: https://go-review.googlesource.com/c/exp/+/273288
Run-TryBot: Jean de Klerk <deklerk@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
Trust: Jean de Klerk <deklerk@google.com>
9 files changed
tree: 437cc590c51242113b19cc9d3abd92035ab18d5c
  1. .gitattributes
  2. .gitignore
  3. AUTHORS
  4. CONTRIBUTING.md
  5. CONTRIBUTORS
  6. LICENSE
  7. PATENTS
  8. README.md
  9. apidiff/
  10. cmd/
  11. codereview.cfg
  12. ebnf/
  13. ebnflint/
  14. errors/
  15. fsnotify/
  16. go.mod
  17. go.sum
  18. inotify/
  19. io/
  20. mmap/
  21. rand/
  22. shiny/
  23. shootout/
  24. sumdb/
  25. utf8string/
  26. winfsnotify/
README.md

exp

PkgGoDev

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.