[BUG] oieserver.sh fails on OS X

[mgaffigan]

Running ./oieserver in server/setup after build yields the error below on Apple bash:

mgaffigan@mbp setup % ./oieserver 
./oieserver: line 102: conditional binary operator expected
./oieserver: line 102: syntax error near `"$var_name"'
./oieserver: line 102: `        if [[ -v "$var_name" ]]; then'
mgaffigan@mbp setup %

[kpalang]

What version of bash do you have installed?

[mgaffigan]

mgaffigan@mbp ~ % bash --version
GNU bash, version 3.2.57(1)-release (arm64-apple-darwin25)
Copyright (C) 2007 Free Software Foundation, Inc.

Why does Apple ship bash 3.2?

[kpalang]

I've approved #199

For future reference, the approach used before this PR works starting with Bash 4.2, but MacOS ships with Bash 3.2.

[gibson9583]

Fun - I hadn't noticed this on Mac since I've been using zsh instead