Builtin rb_tree_* symbols collide with libc on NetBSD

[stixpjr]

I ran into this issue with a strange crash while porting PrusaSlicer to NetBSD, as reported here.

NetBSD libc exports a rb_tree implementation whose weak symbols collide with those in nlopt.
As detailed in that email thread, I worked around the issue by prefixing nlopt's "rb_tree" symbols with "nlopt_", and I'll work on getting that patch into pkgsrc for the current version.

Is there any chance of permanently prefixing nlopt's built-in rb_tree symbols?

[jschueller]

absolutely, can you submit the patch ?