A Go 1.21 feature that I’d previously missed: toolchains. A toolchain consists of a bundled compiler, assembler, and set of standard Go tooling. An installed go command has a bundled toolchain, but is capable of fetching other ones as necessary.

Today, to upgrade my project to Go 1.22, all I had to do was change one line in go.mod:

$ git diff
diff --git a/go.mod b/go.mod
index 49a960839..f1b3ff857 100644
--- a/go.mod
+++ b/go.mod
@@ -11,7 +11,7 @@

 module github.com/crunchydata/priv-all-platform

-go 1.21
+go 1.22.0

The next Go command I ran detected the absence of Go 1.22, and downloaded it, producing the most streamlined upgrade path of all time.

$ go version
go version go1.22.0 darwin/arm64