diff --git a/tools/commands.js b/tools/commands.js
index cf96de00ed..580ffc243c 100644
--- a/tools/commands.js
+++ b/tools/commands.js
@@ -583,7 +583,7 @@ main.registerCommand({
 
     if (! versionInfo) {
       process.stderr.write(
-constraint.packageName + constraint.versionConstraint  + ": no such version\n");
+constraint.packageName + "@" + constraint.versionConstraint  + ": no such version\n");
       process.exit(1);
     }
 
@@ -623,20 +623,24 @@ constraint.packageName + constraint.versionConstraint  + ": no such version\n");
           process.exit(1);
         }
 
-        var buildInfo = cat.getAnyBuild(packageName, version);
-        if (! buildInfo) {
-          process.stderr.write("This package has no build at this version");
+        // Make sure we have enough builds of the package downloaded such that
+        // we can load a browser slice and a slice that will run on this
+        // system. (Later we may also need to download more builds to be able to
+        // deploy to another architecture.)
+        var available = tropohouse.maybeDownloadPackageForArchitectures(
+          versionInfo, ['browser', archinfo.host()]);
+        if (! available) {
+          // XXX maybe we shouldn't be letting the constraint solver choose
+          // things that don't have the right arches?
+          process.stderr.write("Package " + packageName +
+                               " has no compatible build for version " +
+                               version);
           process.exit(1);
         }
 
-        // If the tarball is not in the warehouse, download it there.
-        if (! tropohouse.hasSpecifiedBuild(packageName, version,
-                                           buildInfo.architecture)) {
-           tropohouse.downloadSpecifiedBuild(packageName, version, buildInfo);
-        }
 
-        process.stdout.write("Added :" + packageName + " at " + version + "\n");
-      })
+        process.stdout.write("Added: " + packageName + " at " + version + "\n");
+      });
 
       // Write the new indirect dependencies file.
       project.rewriteIndirectDependencies(options.appDir, newVersions);
diff --git a/tools/tropohouse.js b/tools/tropohouse.js
index 7ddd383cf7..a5cf3f775d 100644
--- a/tools/tropohouse.js
+++ b/tools/tropohouse.js
@@ -9,6 +9,7 @@ var utils = require('./utils.js');
 var updater = require('./updater.js');
 var httpHelpers = require('./http-helpers.js');
 var fiberHelpers = require('./fiber-helpers.js');
+var release = require('./release.js');
 
 var tropohouse = exports;
 
@@ -25,7 +26,7 @@ tropohouse.getWarehouseDir = function () {
   return path.join(warehouseBase, ".meteor");
 };
 
-tropohouse.calculatePath= function(packageName, version, archString) {
+tropohouse.calculatePath = function(packageName, version, archString) {
   var uniquePath = path.join(packageName, version, archString);
   var fullPath = path.join(tropohouse.getWarehouseDir(), "packages", uniquePath);
   return fullPath;
@@ -47,3 +48,26 @@ tropohouse.downloadSpecifiedBuild = function(packageName, version, buildRecord)
   // XXX: if there is a plus in archstring, split and for each one that does not exist, split into symlink.
   // XXX: make atomic.
 };
+
+// Returns true if we now have the package.
+// XXX more precise error handling in offline case. maybe throw instead like
+// warehouse does.
+tropohouse.maybeDownloadPackageForArchitectures = function (versionInfo,
+                                                            architectures) {
+  var cat = release.current.catalog;
+  var buildInfo = cat.getAnyBuild(versionInfo.packageName, versionInfo.version);
+  if (! buildInfo) {
+    return false;
+  }
+
+  // If the tarball is not in the warehouse, download it there.
+  if (tropohouse.hasSpecifiedBuild(versionInfo.packageName,versionInfo.version,
+                                   buildInfo.architecture)) {
+    return true;
+  }
+
+  // XXX error handling
+  tropohouse.downloadSpecifiedBuild(
+    versionInfo.packageName, versionInfo.version, buildInfo);
+  return true;
+};