Issue #272: Provide a flag to opt-in to resolving for current os/arch

glide.go

diff --git a/glide.go b/glide.go
index 4a29d06..9fe1e47 100644
--- a/glide.go
+++ b/glide.go
@@ -43,6 +43,7 @@
 	"github.com/Masterminds/glide/msg"
 	gpath "github.com/Masterminds/glide/path"
 	"github.com/Masterminds/glide/repo"
+	"github.com/Masterminds/glide/util"
 
 	"github.com/codegangsta/cli"
 
@@ -202,6 +203,10 @@
 					Name:  "use-gopath",
 					Usage: "Copy dependencies from the GOPATH if they exist there.",
 				},
+				cli.BoolFlag{
+					Name:  "resolve-current",
+					Usage: "Resolve dependencies for only the current system rather than all build modes.",
+				},
 			},
 			Action: func(c *cli.Context) {
 				if len(c.Args()) < 1 {
@@ -209,6 +214,11 @@
 					os.Exit(1)
 				}
 
+				if c.Bool("resolve-current") {
+					util.ResolveCurrent = true
+					msg.Warn("Only resolving dependencies for the current OS/Arch")
+				}
+
 				inst := &repo.Installer{
 					Force:           c.Bool("force"),
 					UseCache:        c.Bool("cache"),
@@ -465,8 +475,18 @@
 					Name:  "use-gopath",
 					Usage: "Copy dependencies from the GOPATH if they exist there.",
 				},
+				cli.BoolFlag{
+					Name:  "resolve-current",
+					Usage: "Resolve dependencies for only the current system rather than all build modes.",
+				},
 			},
 			Action: func(c *cli.Context) {
+
+				if c.Bool("resolve-current") {
+					util.ResolveCurrent = true
+					msg.Warn("Only resolving dependencies for the current OS/Arch")
+				}
+
 				installer := &repo.Installer{
 					DeleteUnused:    c.Bool("deleteOptIn"),
 					UpdateVendored:  c.Bool("update-vendored"),

util/util.go

diff --git a/util/util.go b/util/util.go
index c16c4db..d73001a 100644
--- a/util/util.go
+++ b/util/util.go
@@ -16,6 +16,12 @@
 	"github.com/Masterminds/vcs"
 )
 
+// ResolveCurrent selects whether the package should only the dependencies for
+// the current OS/ARCH instead of all possible permutations.
+// This is not concurrently safe which is ok for the current application. If
+// other needs arise it may need to be re-written.
+var ResolveCurrent = false
+
 func init() {
 	// Precompile the regular expressions used to check VCS locations.
 	for _, v := range vcsList {
@@ -263,9 +269,13 @@
 func GetBuildContext() (*BuildCtxt, error) {
 	buildContext := &BuildCtxt{build.Default}
 
-	// This tells the context scanning to skip filtering on +build flags or
-	// file names.
-	buildContext.UseAllFiles = true
+	// If we aren't resolving for the current system set to look at all
+	// build modes.
+	if !ResolveCurrent {
+		// This tells the context scanning to skip filtering on +build flags or
+		// file names.
+		buildContext.UseAllFiles = true
+	}
 
 	if goRoot := os.Getenv("GOROOT"); len(goRoot) == 0 {
 		out, err := exec.Command("go", "env", "GOROOT").Output()