build-style/go: support building multiple packages

Manual.md

@@ -1005,8 +1005,8 @@ The following variables influence how Go packages are built:
   distfile, as it would be used with `go get`. For example, GitHub's
   `hub` program has the import path `github.com/github/hub`. This
   variable is required.
-- `go_package`: The import path of the package that should be built.
-  Defaults to `go_import_path`.
+- `go_package`: A space-separated list of import paths of the packages
+  that should be built. Defaults to `go_import_path`.
 - `go_get`: If set to yes, the package specified via `go_import_path`
   will be downloaded with `go get`. Otherwise, a distfile has to be
   provided. This option should only be used with `-git` (or similar)

common/build-style/go.sh

@@ -10,13 +10,11 @@ do_build() {
 	fi
 
 	go_package=${go_package:-$go_import_path}
-	cd "${GOPATH}/src/${go_package}"
-	go get -d "${go_package}"
-	go build -x "${go_package}"
+	go get -x ${go_package}
 }
 
 do_install() {
-	go_package=${go_package:-$go_import_path}
-	cd "${GOPATH}/src/${go_package}"
-	vbin ${pkgname}
+	for f in "${GOBIN}"/*; do
+		vbin "$f"
+	done
 }

common/environment/build-style/go.sh

@@ -12,3 +12,4 @@ case "$XBPS_TARGET_MACHINE" in
 esac
 
 export GOPATH="${wrksrc}/_build-${pkgname}-xbps"
+export GOBIN="${wrksrc}/_build-${pkgname}-xbps-bin"