[OS X] ffi path discovery OSX

[akhenakh]

I'm using Macports in OSX so most of my libs are located in /opt/local
I have to load the shared liquid dsp lib by its full path for luaradio to detect it.

lib_available, lib = pcall(ffi.load, "/opt/local/lib/libliquid.dylib")
if lib_available then
  platform.libs["liquid"] = lib
  platform.features["liquid"] = true
end

I've tried LD_LIBRARY_PATH to avoid patching with no luck, I'm not very familiar with luajit.
Thanks.

[vsergeev]

I think in Mac OS X's case, the equivalent environment variable is DYLD_LIBRARY_PATH. Another option may be to add /opt/local/lib to Mac OS X's equivalent of /etc/ld.so.conf and rerunning Mac OS X's equivalent of sudo ldconfig... Unfortunately, I don't have a Mac to test on.

[akhenakh]

tried DYLD_FALLBACK_LIBRARY_PATH & DYLD_LIBRARY_PATH with no result.
Thanks for the tip anyway

[rht]

You could manually set LDFLAGS to include -L/opt/local/lib and/or CFLAGS/CPPFLAGS to include -I/opt/local/include. Though this could be set in macports config as well.

[n7ihq]

You can make symbolic links: from /opt/local/lib to /usr/local/lib:
sudo ln -s /opt/local/lib/libvolk.dylib /usr/local/lib/libvolk.dylib
sudo ln -a /opt/local/lib/libliquid.dylib /usr/local/lib/libliquid.dylib

[rfc6919]

This issue is the result of macOS stripping environment variables that control dyld from the environment whenever a System Integrity Protection protected binary is executed (see the dyld(1) manpage). In this case, the problem is LD_LIBRARY_PATH and DYLD_LIBRARY_PATH being stripped when /usr/bin/env is executed through the luaradio shebang.

I'm not sure of a good general solution here, but the way I'm working around it is changing the luaradio shebang from #!/usr/bin/env luajit to #!/opt/brew/bin/luajit so my LD_LIBRARY_PATH=/opt/brew/lib isn't stripped out by the extra exec via env(1).

A simple reduction of this problem is:

XYZZY=foobar env | grep XYZZY => prints XYZZY=foobar
LD_LIBRARY_PATH=foobar env | grep LD_LIBRARY_PATH => prints nothing

or, assuming your libraries are in /opt/brew/lib, the actual ffi.load("liquid") failure:

LD_LIBRARY_PATH=/opt/brew/lib luajit -e 'require("ffi").load("liquid")' => succeeds
LD_LIBRARY_PATH=/opt/brew/lib env luajit -e 'require("ffi").load("liquid")' => error

[vsergeev]

Package added to MacPorts with macports/macports-ports#6539 with a wrapper script to fix dynamic library loading in LuaRadio.