go-clone/README.md

# go-clone
5 years earlier, [gohack](https://github.com/rogpeppe/gohack) was written for the same reasons
this tool was written.  gohack has a good justification for this kind of tool so here it is:


## Gohack: mutable checkouts of Go module dependencies

The new Go module system is awesome. It ensures repeatable, deterministic
builds of Go code. External module code is cached locally in a read-only
directory, which is great for reproducibility. But if you're used to the
global mutable namespace that is `$GOPATH`, there's an obvious question:
what if I'm hacking on my program and I *want* to change one of those
external modules?

You might want to put a sneaky `log.Printf` statement to find out how
some internal data structure works, or perhaps try out a bug fix to see
if it solves your latest problem. But since all those external modules
are in read-only directories, it's hard to change them. And you really
don't want to change them anyway, because that will break the integrity
checking that the Go tool does when building.

Luckily the modules system provides a way around this: you can add a
`replace` statement to the `go.mod` file which substitutes the contents
of a directory holding a module for the readonly cached copy. You can of
course do this manually, but gohack aims to make this process pain-free.

## Install go-glone

	go install go.wit.com/apps/go-clone@latest

## go-glone itself

This will make a work directory and download everything needs to compile
go-clone.

	go-clone --work go.wit.com/apps/go-clone