I get a strange warning about MACOSX_DEPLOYMENT_TARGET - what's wrong?

Relevant for Mac OS 10.2 users only.

You might get the following warning when building your application:

ld: warning dynamic shared library:
/System/Library/Frameworks/AGL.framework/AGL not made a weak library
in output with MACOSX_DEPLOYMENT_TARGET environment variable set to:
10.1

This has nothing to do with Coin, it's an issue with the Mac OS X "December 2002" developer tools. The warning is totally harmless. You can ignore it, or you can set the environment variable MACOSX_DEPLOYMENT_TARGET="10.2". (FYI, it essentially has to do with how missing symbols at startup are handled. Please read the relevant TechNote if you are interested in background information.)