The Go linker (go tool ld) has an option to set the value of an uninitialised string variable:

-X symbol value
Set the value of an otherwise uninitialized string variable.
The symbol name should be of the form importpath.name,
as displayed in the symbol table printed by "go tool nm".

As part of your build process, you could set a version string variable using this. You can pass this through the go tool using -ldflags. For example, given the following source file:

package main

import "fmt"

var xyz string

func main() {
    fmt.Println(xyz)
}

Then:

$ go run -ldflags "-X main.xyz abc" main.go
abc

I don't think it's possible in go.

Maybe you can have a version.go which contains a Build variable, and your build script will increment it before running go build? (by some clever perl/sed/awk one liner).

Not with Go's own tool chain. You'll have to hook a script into your build setup somewhere that could do it.

You can write one in Go itself. This is how I would go about it:

• Once you start a build cycle, hook this tool in there somewhere.
• Use the source parsing packages to create an AST of your main.go.
• Traverse it and find a specific variable or constant you have reserved for the version information.
• Extract the version value, parse it into integers and increment where necessary.
• Write the changes back to the AST.
• Write the entire AST back into the file as source code (this is what gofmt does).
• Exit this little tool and continue with the build process.