On Tue, Nov 06, 2018 at 06:33:53PM +0100, Pierre Neidhardt wrote:
> > If most of the Go packages are ready for Go 1.11, we could make it the
> > dfeault and then use Go 1.9 for the packages that are lagging behind. Or
> > vice versa.
> 
> How do you do that?

The default Go is defined in ((guix build-system go) default-go).
Updates can be tested with this diff:

diff --git a/guix/build-system/go.scm b/guix/build-system/go.scm
index cf9116327..80894677f 100644
--- a/guix/build-system/go.scm
+++ b/guix/build-system/go.scm
@@ -44,7 +44,7 @@
 (define (default-go)
   ;; Lazily resolve the binding to avoid a circular dependency.
   (let ((go (resolve-interface '(gnu packages golang))))
-    (module-ref go 'go)))
+    (module-ref go 'go-1.11)))
 
 (define* (lower name
                 #:key source inputs native-inputs outputs system target


And individual packages can be made to use non-default Go compilers with
the #:go key, like this:

diff --git a/gnu/packages/curl.scm b/gnu/packages/curl.scm
index 2fb87251f..4c8c83d84 100644
--- a/gnu/packages/curl.scm
+++ b/gnu/packages/curl.scm
@@ -171,6 +171,7 @@ tunneling, and so on.")
     (arguments
      `(#:import-path "gitlab.com/davidjpeacock/kurly"
        #:install-source? #f
+       #:go ,go-1.11
        #:phases
        (modify-phases %standard-phases
          (add-after 'install 'install-documentation