internal/lsp: enable -mod=readonly in workspace module mode

Now that workspace module mode generates a combined go.sum there are
relatively few blockers to enabling -mod=readonly. Fix them and do it.

This CL is a bit of a grab bag, but the fixes are relatively separate. I
can split it into multiple CLs if desired.

- If module A depends on module B at v1.0.0, the go command will want to
upgrade the workspace module from v0.0.0-goplsworkspace to v1.0.0. To
prevent that, use vN.999999.0 as the base pseudoversion, adjusting v0 to
v1 where appropriate. A few test cases needed updating as a result.
- For old Go versions, sort the generated workspace module and
synthesize a go statement from the maximum go version declared in the
- Some regtests need go.sum files created.
- matchErrorToModule created incorrect quick fixes: it would try to
download the top-level module mentioned in the error message, not the
one that actually caused the problem. Now it issues quick fixes for the
lowest-level module.
- TestMultiModuleModDiagnostics accidentally included the same module
in the workspace twice. Fix it, and make that an error.

Fixes golang/go#43346.

Change-Id: I605f762a4d23bedd914241525e64c1b3ecc42150
Trust: Heschi Kreinick <>
Reviewed-by: Robert Findley <>
Reviewed-by: Rebecca Stambler <>
5 files changed
tree: cf8e2cab646e0d2fa0a9a9f79c19fbbfaa854002
  1. .gitattributes
  2. .gitignore
  3. .prettierrc
  10. benchmark/
  11. blog/
  12. cmd/
  13. codereview.cfg
  14. container/
  15. copyright/
  16. cover/
  17. go.mod
  18. go.sum
  19. go/
  20. godoc/
  21. gopls/
  22. imports/
  23. internal/
  24. playground/
  25. present/
  26. refactor/
  27. txtar/

Go Tools


This subrepository holds the source for various packages and tools that support the Go programming language.

Some of the tools, godoc and vet for example, are included in binary Go distributions.

Others, including the Go guru and the test coverage tool, can be fetched with go get.

Packages include a type-checker for Go and an implementation of the Static Single Assignment form (SSA) representation for Go programs.


The easiest way to install is to run go get -u You can also manually git clone the repository to $GOPATH/src/

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