I am setting up pd vanilla to be compatible with some old pd-extended patches.

I got the deken plugin to work and installed zexy and cyclone, I added them to the startup options and zexy loads, but cyclone does not.
I just get the message "cyclone:can't open" in the pd console
I also tried installing with apt-get (I am on linux), I'm not sure what to try next.

Thanks, any help is much appreciated!

Just an update: I had actually installed pd-zexy via the linux terminal earlier, so I removed it from the pd-externals folder that deken was installing to and it still works. I then removed everything from the pd-externals folder, but when I open pd I still have zexy loading fine and cyclone unable to load, although instead of "can't open", it now just says: "cyclone: can't load library"

It is the same for iemlib and ggee. The only libraries that seem to work for me are zexy and bassemu~
Still no luck.

With deken package installed
Go to:
File -> Preferences -> Path

and add the library folder to path

/home/<yourUser>/pd-externals/<theLibraryToBeSet>

This in pd 0.46-7

I had already tried that.

I recently uninstalled and removed everything, then built pd 0.47-0 from the source and tried again, but I am getting the same result. Zexy works but cyclone it says "can't load library"

It seems like the libraries are loading now, I have cyclone working in 0.47 by adding it's subfolder to the path menu. It still says "cyclone: can't load library" in the console if I have cyclone as a startup entry, but if I remove it the error goes away although the library still loads. The other libraries seem to be loading also, except for zexy which seems to need the startup entry.

Ok..

far as I know, we only need to set as startup entry libraries compiled in all in one file style (don't know the right name for these, all objects in one binary). A examples of these libraries is zexy.

Libraries like cyclone have a compilation per object (one binary per object) and I ever set this type libraries by the way I said before.

Was a solution ever reached for this issue? I switched from Extended to Vanilla after Extended started putting MASSIVE strain on my CPU usage for no apparent reason.

Thank you so much for bringing this up, I was stuck. Now I think my system will be up and running in no time. I believe the key file here is libraryname.d_fat **
It is present in zexy, not in the others.

As @emviveros stated, a library in Pd is considered one that has all its objects compiled under one binary. Like the zexy example, where you have one zexy.d_fat, or zexy.pd_darwin binary. These libraries are loaded with the -lib flag under Startup...
Libraries that have one binary per object will work if you include their path to Pd's search path, no need to use the -lib flag. I guess cyclone is like that.
This difference applies to all libraries in Pd.