Merge "Add some notes on DISTRO setting"

functions-common

@@ -390,7 +390,26 @@ function GetDistro {
     elif [[ "$os_VENDOR" =~ (kvmibm) ]]; then
         DISTRO="${os_VENDOR}${os_RELEASE::1}"
     else
-        die $LINENO "Unable to determine DISTRO"
+        # We can't make a good choice here.  Setting a sensible DISTRO
+        # is part of the problem, but not the major issue -- we really
+        # only use DISTRO in the code as a fine-filter.
+        #
+        # The bigger problem is categorising the system into one of
+        # our two big categories as Ubuntu/Debian-ish or
+        # Fedora/CentOS-ish.
+        #
+        # The setting of os_PACKAGE above is only set to "deb" based
+        # on a hard-coded list of vendor names ... thus we will
+        # default to thinking unknown distros are RPM based
+        # (ie. is_ubuntu does not match).  But the platform will then
+        # also not match in is_fedora, because that also has a list of
+        # names.
+        #
+        # So, if you are reading this, getting your distro supported
+        # is really about making sure it matches correctly in these
+        # functions.  Then you can choose a sensible way to construct
+        # DISTRO based on your distros release approach.
+        die $LINENO "Unable to determine DISTRO, can not continue."
     fi
     typeset -xr DISTRO
 }