-r switch doesn't switch to read-only repository

[trysetnull]

Environment

uname -a
Linux 3.2.0-4-amd64 #1 SMP Debian 3.2.54-2 x86_64 GNU/Linux

echo $SHELL
/bin/bash

When I tried to run the cy script I got the following error:

/usr/local/bin/cy: 35: /usr/local/bin/cy: Syntax error: "(" unexpected

I changed the shebang from /bin/sh to /bin/bash and I could run the script.

I tried to use the -r switch but git reported:

 - Using read-only repository.
...
Permission denied (publickey).
fatal: The remote end hung up unexpectedly
Could not clone remote repository

The -r switch only writes a message to stdout.
The script should switch to use NON_CORE_URL (which is a read-only repository) instead of BASE_URL.