Support cross-compile install

src/bin/cargo/commands/install.rs

@@ -32,6 +32,7 @@ pub fn cli() -> App {
             "Install only the specified example",
             "Install all examples",
         )
+        .arg_target_triple("Build for the target triple")
         .arg(opt("root", "Directory to install packages into").value_name("DIR"))
         .after_help(
             "\

tests/testsuite/install.rs

@@ -4,6 +4,7 @@ use std::io::prelude::*;
 
 use cargo::util::ProcessBuilder;
 use cargotest::install::{cargo_home, has_installed_exe};
+use cargotest::support::cross_compile;
 use cargotest::support::git;
 use cargotest::support::paths;
 use cargotest::support::registry::Package;
@@ -1334,6 +1335,40 @@ fn dev_dependencies_lock_file_untouched() {
     assert!(lock == lock2, "different lockfiles");
 }
 
+#[test]
+fn install_target_native() {
+    pkg("foo", "0.1.0");
+
+    assert_that(
+        cargo_process("install")
+            .arg("foo")
+            .arg("--target")
+            .arg(cargotest::rustc_host()),
+        execs()
+            .with_status(0),
+    );
+    assert_that(cargo_home(), has_installed_exe("foo"));
+}
+
+#[test]
+fn install_target_foreign() {
+    if cross_compile::disabled() {
+        return;
+    }
+
+    pkg("foo", "0.1.0");
+
+    assert_that(
+        cargo_process("install")
+            .arg("foo")
+            .arg("--target")
+            .arg(cross_compile::alternate()),
+        execs()
+            .with_status(0),
+    );
+    assert_that(cargo_home(), has_installed_exe("foo"));
+}
+
 #[test]
 fn vers_precise() {
     pkg("foo", "0.1.1");