go/doc
Bryan C. Mills 7dedc237c5 cmd/go: smooth out upgrade paths for lazy loading
This change adds two possible upgrade paths for lazy loading:

1. Run 'go mod tidy -go=1.17'.

2. Starting in a module with no existing 'go' directive,
   run any 'go' command that updates the go.mod file.

In the latter case, commands other than 'go mod tidy'
may leave the go.mod file *very* untidy if it had non-trivial
dependencies. (The 'go' invocation will promote all
implicit eager dependencies to explicit lazy ones,
which preserves the original module graph — most of which is
not actually relevant.)

'go mod tidy -go=1.17' can be used to enable lazy loading without
accidentally downgrading existing transitive dependencies.

'go mod tidy -go=1.16' can be used to disable lazy loading and clear
away redundant roots in a single step (if reducing the go version), or
to prune away dependencies of tests-of-external-tests (if increasing
the go version).

'go mod tidy -go=1.15' can be used to add dependencies of
tests-of-external-tests, although there isn't much point to that.

DO NOT MERGE

This change still needs an explicit test and a release note.

Fixes #45094
For #36460

Change-Id: I68f057e39489dfd6a667cd11dc1e320c1ee1aec1
Reviewed-on: https://go-review.googlesource.com/c/go/+/315210
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Matloob <matloob@golang.org>
2021-04-30 18:06:46 +00:00
..
asm.html doc/asm: add a section on go_asm.h, clean up go_tls.h section 2021-01-25 19:32:27 +00:00
go1.17.html cmd/go: smooth out upgrade paths for lazy loading 2021-04-30 18:06:46 +00:00
go_mem.html doc/mem: remove unnecessary pre tags within same snippet 2020-03-03 09:28:34 +00:00
go_spec.html spec: clarify conditions for switch expression type 2021-04-28 18:50:51 +00:00