only /usr/xpg4/bin/grep and /usr/xpg4/bin/egrep on solaris have -q switch. others (yes, there are more than one grep and egrep on solaris) don't have it.
this is bash syntax, mainly in gitflow-common. you think this is sh because /bin/sh is probably a symlink to bash on your Linux, but sh has different syntax.
Thanks for the help. I was able to get this running with taking the -q option out of the grep calls and moving git-flow from /bin/sh to /bin/bash and git flow is working nicely on Solaris now.