Update minimum bash version

Dean Troyer · Dean Troyer · commit d97ee3095eea · 2015-02-04T12:50:35.000-06:00
Clarify our position on bash and other shells.

Change-Id: I30e801afa03f8d7235556b0933d0205a30310899
diff --git a/HACKING.rst b/HACKING.rst
@@ -6,7 +6,7 @@ General
 -------
 
 DevStack is written in UNIX shell script.  It uses a number of bash-isms
-and so is limited to Bash (version 3 and up) and compatible shells.
+and so is limited to Bash (version 4 and up) and compatible shells.
 Shell script was chosen because it best illustrates the steps used to
 set up and interact with OpenStack components.
 
diff --git a/doc/source/faq.rst b/doc/source/faq.rst
@@ -70,6 +70,18 @@ Q: What about Fedora/RHEL/CentOS?
 Q: Are there any differences between Ubuntu and Fedora support?
     A: Neutron is not fully supported prior to Fedora 18 due lack of
     OpenVSwitch packages.
+Q: Why can't I use another shell?
+    A: DevStack now uses some specific bash-ism that require Bash 4, such
+    as associative arrays. Simple compatibility patches have been accepted
+    in the past when they are not complex, at this point no additional
+    compatibility patches will be considered except for shells matching
+    the array functionality as it is very ingrained in the repo and project
+    management.
+Q: But, but, can't I test on OS/X?
+   A: Yes, even you, core developer who complained about this, needs to
+   install bash 4 via homebrew to keep running tests on OS/X.  Get a Real
+   Operating System.   (For most of you who don't know, I am refering to
+   myself.)
 
 Operation and Configuration
 ===========================
