--- a/python/mozboot/mozboot/android.py
+++ b/python/mozboot/mozboot/android.py
@@ -45,33 +45,35 @@ output as packages are downloaded and in
 MOBILE_ANDROID_MOZCONFIG_TEMPLATE = '''
 Paste the lines between the chevrons (>>> and <<<) into your mozconfig file:
 
 <<<
 # Build Firefox for Android:
 ac_add_options --enable-application=mobile/android
 ac_add_options --target=arm-linux-androideabi
 
+{extra_lines}
 # With the following Android SDK and NDK:
-ac_add_options --with-android-sdk="%s"
-ac_add_options --with-android-ndk="%s"
+ac_add_options --with-android-sdk="{sdk_path}"
+ac_add_options --with-android-ndk="{ndk_path}"
 >>>
 '''
 
 MOBILE_ANDROID_ARTIFACT_MODE_MOZCONFIG_TEMPLATE = '''
 Paste the lines between the chevrons (>>> and <<<) into your mozconfig file:
 
 <<<
 # Build Firefox for Android Artifact Mode:
 ac_add_options --enable-application=mobile/android
 ac_add_options --target=arm-linux-androideabi
 ac_add_options --enable-artifact-builds
 
+{extra_lines}
 # With the following Android SDK:
-ac_add_options --with-android-sdk="%s"
+ac_add_options --with-android-sdk="{sdk_path}"
 
 # Write build artifacts to:
 mk_add_options MOZ_OBJDIR=./objdir-frontend
 >>>
 '''
 
 
 def install_mobile_android_sdk_or_ndk(url, path):
@@ -259,22 +261,39 @@ def ensure_android_packages(sdkmanager_t
         cmd = args[0]
         e = subprocess.CalledProcessError(retcode, cmd)
         e.output = output
         raise e
 
     print(output)
 
 
-def suggest_mozconfig(os_name, artifact_mode=False):
+def suggest_mozconfig(os_name, artifact_mode=False, java_bin_path=None):
     _mozbuild_path, sdk_path, ndk_path = get_paths(os_name)
+
+    extra_lines = []
+    if java_bin_path:
+        extra_lines += [
+            '# With the following java and javac:',
+            'ac_add_options --with-java-bin-path="{}"'.format(java_bin_path),
+        ]
+    if extra_lines:
+        extra_lines.append('')
+
     if artifact_mode:
-        print(MOBILE_ANDROID_ARTIFACT_MODE_MOZCONFIG_TEMPLATE % (sdk_path))
+        template = MOBILE_ANDROID_ARTIFACT_MODE_MOZCONFIG_TEMPLATE
     else:
-        print(MOBILE_ANDROID_MOZCONFIG_TEMPLATE % (sdk_path, ndk_path))
+        template = MOBILE_ANDROID_MOZCONFIG_TEMPLATE
+
+    kwargs = dict(
+        sdk_path=sdk_path,
+        ndk_path=ndk_path,
+        extra_lines='\n'.join(extra_lines),
+    )
+    print(template.format(**kwargs))
 
 
 def android_ndk_url(os_name, ver=NDK_VERSION):
     # Produce a URL like
     # 'https://dl.google.com/android/repository/android-ndk-$VER-linux-x86_64.zip
     base_url = 'https://dl.google.com/android/repository/android-ndk'
 
     if os_name == 'macosx':

--- a/python/mozboot/mozboot/osx.py
+++ b/python/mozboot/mozboot/osx.py
@@ -284,19 +284,25 @@ class OSXBootstrapper(BaseBootstrapper):
                 print(INSTALL_XCODE_COMMAND_LINE_TOOLS_STEPS)
                 sys.exit(1)
 
     def _install_xcode_app_store(self):
         subprocess.check_call(['open', XCODE_APP_STORE])
         print('Once the install has finished, please relaunch this script.')
         sys.exit(1)
 
+    def _ensure_homebrew_found(self):
+        if not hasattr(self, 'brew'):
+            self.brew = self.which('brew')
+        # Earlier code that checks for valid package managers ensures
+        # which('brew') is found.
+        assert self.brew is not None
+
     def _ensure_homebrew_packages(self, packages, extra_brew_args=[]):
-        self.brew = self.which('brew')
-        assert self.brew is not None
+        self._ensure_homebrew_found()
         cmd = [self.brew] + extra_brew_args
 
         installed = self.check_output(cmd + ['list']).split()
 
         printed = False
 
         for package in packages:
             if package in installed:
@@ -306,16 +312,22 @@ class OSXBootstrapper(BaseBootstrapper):
                 print(PACKAGE_MANAGER_PACKAGES % ('Homebrew',))
                 printed = True
 
             subprocess.check_call(cmd + ['install', package])
 
         return printed
 
     def _ensure_homebrew_casks(self, casks):
+        self._ensure_homebrew_found()
+
+        # Ensure that we can access old versions of packages.  This is
+        # idempotent, so no need to avoid repeat invocation.
+        self.check_output([self.brew, 'tap', 'caskroom/versions'])
+
         # Change |brew install cask| into |brew cask install cask|.
         return self._ensure_homebrew_packages(casks, extra_brew_args=['cask'])
 
     def ensure_homebrew_system_packages(self):
         packages = [
             # We need to install Python because Mercurial requires the Python
             # development headers which are missing from OS X (at least on
             # 10.8) and because the build system wants a version newer than
@@ -364,17 +376,19 @@ class OSXBootstrapper(BaseBootstrapper):
 
         # 2. Android pieces.
         from mozboot import android
         android.ensure_android('macosx', artifact_mode=artifact_mode,
                                no_interactive=self.no_interactive)
 
     def suggest_homebrew_mobile_android_mozconfig(self, artifact_mode=False):
         from mozboot import android
-        android.suggest_mozconfig('macosx', artifact_mode=artifact_mode)
+        # Path to java and javac from the caskroom/versions/java8 cask.
+        android.suggest_mozconfig('macosx', artifact_mode=artifact_mode,
+                                  java_bin_path='/Library/Java/Home/bin')
 
     def _ensure_macports_packages(self, packages):
         self.port = self.which('port')
         assert self.port is not None
 
         installed = set(self.check_output([self.port, 'installed']).split())
 
         missing = [package for package in packages if package not in installed]