Can now specify upstream of anyname through -u/--upstream flag

lib/spack/spack/cmd/install.py

@@ -39,7 +39,8 @@ def update_kwargs_from_args(args, kwargs):
         'fake': args.fake,
         'dirty': args.dirty,
         'use_cache': args.use_cache,
-        'install_global': args.install_global
+        'install_global': args.install_global,
+        'upstream': args.upstream
     })
     if hasattr(args, 'setup'):
         setups = set()

lib/spack/spack/cmd/uninstall.py

@@ -94,7 +94,12 @@ def find_matching_specs(env, specs, allow_multiple_matches=False, force=False,
         spack.config.set('config:active_tree', global_root,
                          scope='user')
     elif upstream:
-        raise NotImplementedError
+        if upstream not in spack.config.get('upstreams'):
+            tty.die("specified upstream does not exist")
+        root = spack.config.get('upstreams')
+        root = root[upstream]['install_tree']
+        root = spack.util.path.canonicalize_path(root)
+        spack.config.set('config:active_tree', root, scope='user')
     else:
         for spec in specs:
             if isinstance(spec, spack.spec.Spec):

lib/spack/spack/package.py

@@ -1492,7 +1492,7 @@ def do_install(self, **kwargs):
         dirty = kwargs.get('dirty', False)
         restage = kwargs.get('restage', False)
         install_global = kwargs.get('install_global', False)
-        upstream = kwargs.get('upstream', False)
+        upstream = kwargs.get('upstream', None)
 
         # Install Package to Global Upstream for multi-user use
         if install_global:
@@ -1502,7 +1502,12 @@ def do_install(self, **kwargs):
             spack.config.set('config:active_tree', global_root,
                              scope='user')
         elif upstream:
-            raise NotImplementedError
+            if upstream not in spack.config.get('upstreams'):
+                tty.die("specified upstream does not exist")
+            root = spack.config.get('upstreams')
+            root = root[upstream]['install_tree']
+            root = spack.util.path.canonicalize_path(root)
+            spack.config.set('config:active_tree', root, scope='user')
         else:
             spack.config.set('config:active_tree',
                              spack.config.get('config:install_tree'),