Use `grep -R` to follow apt source symlinks.
Use `grep -R` to follow apt source symlinks.

In newer greps, '-r' only follows commandline arg symlinks.

http://git.savannah.gnu.org/cgit/grep.git/commit/?id=c6e3ea61d9f08aa0128a0eb13d31a2fbad376f99

closes gh-270

victorklos/babushka,victorklos/babushka,victorklos/babushka