Instructions on avoiding exception when running mojo on Marshmallow.

README.md

 Mojo
 ====
 
 Mojo is an effort to extract a common platform out of Chrome's renderer and
 plugin processes that can support multiple types of sandboxed content, such as
 HTML, Pepper, or NaCl.
 
 ## Set-up and code check-out
 
 The instructions below only need to be done once. Note that a simple "git clone"
@@ skipping 92 matching lines @@
 To build for Android, first make sure that your checkout is [configured](#configure-android) to build
 for Android. After that you can use the mojob script as follows:
 ```
 $ mojo/tools/mojob.py gn --android
 $ mojo/tools/mojob.py build --android
 ```
 
 The result will be in out/android_Debug. If you see javac compile errors,
 [make sure you have an up-to-date JDK](https://code.google.com/p/chromium/wiki/AndroidBuildInstructions#Install_Java_JDK)
 
+#### Marshmallow
+Running mojo on Marshmallow might raise an Exception `"Unable to find fifo"`. As
+a temporary solution, you can go to `Settings` -> `Apps` -> `Mojo Shell (dev)`
+-> `Permissions` and allow for `Storage`.
+
+*Explanation*: Starting in API level 23 (Marshmallow) the applications need to

[etiennej, 2015/10/30 16:20:28]

I don't think you should put explanation here. I suggest you put the explanation
in the bug, and put a link to the bug here ("see this bug for more
information").

+request read/write permissions at runtime. An exception to this rule is for
+files stored in the folder returned by method [Context.getExternalFilesDir(String)](http://developer.android.com/reference/android/content/Context.html#getExternalFilesDir(java.lang.String))
+which can be used without permissions. This folder looks like 
+`"/storage/emulated/0/Android/data/org.chromium.mojo.shell/files"`. Ideally we
+should write files (e.g. the argument's file, used when starting the application)
+in this directory. However, for some reasons, we cannot do it for now when the
+phone is not rooted. As a temporary fix, you can manually add storage permissions
+for the Mojo Shell app the exception should disappear.
+
 ### Goma (Googlers only)
 
 If you're a Googler, you can use Goma, a distributed compiler service for
 open-source projects such as Chrome and Android. If Goma is installed in the
 default location (~/goma), it will work out-of-the-box with the `mojob.py gn`,
 `mojob.py build` workflow described above.
 
 You can also manually add:
 ```
 use_goma = true
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 making your first change: [C++ in Chromium
 101](http://dev.chromium.org/developers/cpp-in-chromium-101-codelab).
 
 To land a change after receiving LGTM:
 ```
 $ git cl land
 ```
 
 Don't break the build! Waterfall is here:
 http://build.chromium.org/p/client.mojo/waterfall