diff -Naur a/tools/gyp/pylib/gyp/xcode_emulation.py b/tools/gyp/pylib/gyp/xcode_emulation.py
--- a/tools/gyp/pylib/gyp/xcode_emulation.py	2013-11-12 21:22:12.000000000 +0100
+++ b/tools/gyp/pylib/gyp/xcode_emulation.py	2013-12-17 11:07:11.000000000 +0100
@@ -285,8 +285,15 @@
     if sdk_root.startswith('/'):
       return sdk_root
     if sdk_root not in XcodeSettings._sdk_path_cache:
-      XcodeSettings._sdk_path_cache[sdk_root] = self._GetSdkVersionInfoItem(
-          sdk_root, 'Path')
+      try:
+        XcodeSettings._sdk_path_cache[sdk_root] = self._GetSdkVersionInfoItem(
+            sdk_root, 'Path')
+      except:
+        # if this fails it's because xcodebuild failed, which means
+        # the user is probably on a CLT-only system, where there
+        # is no valid SDK root
+        XcodeSettings._sdk_path_cache[sdk_root] = None
+
     return XcodeSettings._sdk_path_cache[sdk_root]
 
   def _AppendPlatformVersionMinFlags(self, lst):
@@ -397,10 +404,11 @@
 
     cflags += self._Settings().get('WARNING_CFLAGS', [])
 
-    config = self.spec['configurations'][self.configname]
-    framework_dirs = config.get('mac_framework_dirs', [])
-    for directory in framework_dirs:
-      cflags.append('-F' + directory.replace('$(SDKROOT)', sdk_root))
+    if 'SDKROOT' in self._Settings():
+      config = self.spec['configurations'][self.configname]
+      framework_dirs = config.get('mac_framework_dirs', [])
+      for directory in framework_dirs:
+        cflags.append('-F' + directory.replace('$(SDKROOT)', sdk_root))
 
     self.configname = None
     return cflags
@@ -647,10 +655,11 @@
     for rpath in self._Settings().get('LD_RUNPATH_SEARCH_PATHS', []):
       ldflags.append('-Wl,-rpath,' + rpath)
 
-    config = self.spec['configurations'][self.configname]
-    framework_dirs = config.get('mac_framework_dirs', [])
-    for directory in framework_dirs:
-      ldflags.append('-F' + directory.replace('$(SDKROOT)', self._SdkPath()))
+    if 'SDKROOT' in self._Settings():
+      config = self.spec['configurations'][self.configname]
+      framework_dirs = config.get('mac_framework_dirs', [])
+      for directory in framework_dirs:
+        ldflags.append('-F' + directory.replace('$(SDKROOT)', self._SdkPath()))
 
     self.configname = None
     return ldflags
@@ -826,7 +835,10 @@
         l = '-l' + m.group(1)
       else:
         l = library
-    return l.replace('$(SDKROOT)', self._SdkPath(config_name))
+    if self._SdkPath():
+      return l.replace('$(SDKROOT)', self._SdkPath(config_name))
+    else:
+      return l
 
   def AdjustLibraries(self, libraries, config_name=None):
     """Transforms entries like 'Cocoa.framework' in libraries into entries like