ZMQ Shared Library Location

[quinnj]

Not sure if this is the right place, but I'm trying to iron out some wrinkles in the IJulia frontend in Sublime Text. I have a sublime plugin that loads the ZMQ from the IJulia package install, but it seems that the ZMQ library doesn't always get put in the same place. So far, it looks like windows and linux both get the library in .julia/ZMQ/deps/usr/lib, but osx (through homebrew) installs it in the usr/local directory, but sometimes in different directories? (a question because I'm not exactly sure what happens here other than I've had 2 people find it in different places on their system).

Is there a reliable and cross-platform way to find the shared library after a user has successfully built/installed ZMQ/IJulia?

[StefanKarpinski]

cc: @loladiro, @staticfloat

[Keno]

ZMQ.zmq from Julia, other than that no, since we have given up on uniform installation locations.

[StefanKarpinski]

That's an unfortunate situation. Can we do something about that so that we do have uniform installation locations?

[Keno]

No, that's pretty much totally unfeasibly, especially since we try to use system libraries where possible.

[staticfloat]

Different OS'es have different standards, so like @loladiro says we don't really do uniform installation locations, especially since if users already have a working libzmq on their system BinDeps won't even try to build it again, so it might not even be in the ~/.julia/ directory at all.

I would really like a way to turn a dlopen()'ed handle into a library path, but as of yet we don't have anything like that. The closest thing we do have is this PR I just opened.

[StefanKarpinski]

@loladiro – are you talking about the libraries we install or the system libraries? My impression is that the issue here is that we are installing libraries under .julia in inconsistent places across different operating systems. If dlopen is able to find libraries, then other things must also be able to do so, in which case, can't we expose that information to the user?

[StefanKarpinski]

Ah, you already answered my question by the time I posted it. Thanks, @staticfloat and @loladiro.

[quinnj]

So for this situation though, if the user has successfully built ZMQ/IJulia, that means they either have the shared library in the deps/usr/lib directory (sometimes on linux, probably always on windows), or will be a system library. In the case of the latter, does that mean the library will be available on the path? (I'm trying to think through how I can reliably check/find the library....). I guess if not, I can just have a package setting where the user can specify their zmq shared library path, though I was hoping to avoid having to do that at all.

[Keno]

You can have that option and auto-populate it with the value of ZMQ.zmq.

[quinnj]

Yeah, that should work. I was thinking of having a script run to install IJulia if it wasn't anyway, so I'll fold the ZMQ finding in as well. Thanks for the responses.