This program, dist, is the bootstrapping tool for the Go distribution.
As of Go 1.5, dist and other parts of the compiler toolchain are written in Go, making bootstrapping a little more involved than in the past. The approach is to build the current release of Go with an earlier one.
The process to install Go 1.x, for x ≥ 20, is:
NOTE: During the transition from the old C-based toolchain to the Go-based one, step 2 also builds the parts of the toolchain written in C, and step 3 does not recompile those.
Because of backward compatibility, although the steps above say Go 1.17.13, in practice any release ≥ Go 1.17.13 but < Go 1.x will work as the bootstrap base.
See golang.org/s/go15bootstrap for more details.
Compared to Go 1.4 and earlier, dist will also take over much of what used to be done by make.bash/make.bat/make.rc and all of what used to be done by run.bash/run.bat/run.rc, because it is nicer to implement that logic in Go than in three different scripting languages simultaneously.