build-system/go: Build with a filesystem union of Go dependencies.

This basically changes (guix build-system go) so that instead of looking
up its dependencies in a list of directories in $GOPATH, all the
Go dependencies are symlinked into a single directory.

Fixes <https://bugs.gnu.org/33620>.

* guix/build/go-build-system.scm (setup-go-environment): New variable.
(setup-environment, install-source): Remove variables.
(unpack): Unpack the source relative to $GOPATH.
(install): Do not install the compiled objects in the 'pkg' directory.
Install the source code in this phase, and only install the source of
the package named by IMPORT-PATH.
* doc/guix.texi (Build Systems): Adjust accordingly.
* gnu/packages/docker.scm (docker): Import (guix build union) on the build side
and adjust to build phase name changes in (guix build-system go).
* gnu/packages/shellutils.scm (direnv): Likewise.
* gnu/packages/databases.scm (mongo-tools)[arguments]:
Set '#:install-source #f'.
* gnu/packages/music.scm (demlo)[arguments]: Move the 'install-scripts'
phase after the 'install' phase.

1 files changed, 2 insertions, 2 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 043aad1b65..a720f3f3bb 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -5791,8 +5791,8 @@ some cases, you will need to unpack the package's source code to a
 different directory structure than the one indicated by the import path,
 and @code{#:unpack-path} should be used in such cases.
 
-Packages that provide Go libraries should be installed along with their
-source code.  The key @code{#:install-source?}, which defaults to
+Packages that provide Go libraries should install their source code into
+the built output.  The key @code{#:install-source?}, which defaults to
 @code{#t}, controls whether or not the source code is installed.  It can
 be set to @code{#f} for packages that only provide executable files.
 @end defvr