www.neuron.yale.edu

Hello,

Some weeks ago, I compiled a mod (hhSV.mod) I based on the original hh mod file file by dragging it on mknrndll. Loading neuron from python (from neuron import *) resulted in the message "Additional mechanisms from files; hhSV.mod" and everything worked fine.
Now, I copied my project to a new folder, modified the mod file, and tried to redo the procedure. Now, when I try to load neuron from python, I get the following error:
dlopen failed -
dlopen(x86_64/.libs/libnrnmech.so, 2): Symbol not found: __ZN9ivPrinterC1EPSo
Referenced from: /Applications/NEURON-7.3/nrn/x86_64/lib/libivoc.0.dylib
Expected in: flat namespace
in /Applications/NEURON-7.3/nrn/x86_64/lib/libivoc.0.dylib
Using the old mod file results in the same error. Oddly, running special.exe in the x86_64 folder generated by mknrndll, does work without errors.

I use neuron 7.3, OSX 10.9.5 and python 2.7.8.

Any help would be greatly appreciated, cause I have no clue what happened.

Regards,
Bas-Jan

Delete the x86_64 directory and its contents, then recompile the mod file. BTW, suggest you do that by dropping the entire folder on mknrndll, which will compile all mod files that are in the folder.

Hello Ted,

Thanks for the fast response, greatly appreciate the help. However, the error persists. I rebooted my machine, removed the x86_64 folder, then dragged my project folder on mknrndll.

One more thing I forgot to mention: I used a longer folder name earlier, which resulted in an error that the file Documents\first halfofquitelongfoldername(weird series of characters).mod could not be found. A bit farfetched maybe, but could this have broken something?

Cheers,
Bas-Jan

Suggest trying one of these
--get the latest alpha dmg for OS X and install NEURON from that
http://www.neuron.yale.edu/ftp/neuron/v ... 10.9.5.dmg
or
--download and compile NEURON's latest source code from its mercurial repository (see
http://www.neuron.yale.edu/neuron/download/getdevel
)

Thanks for your help Ted. Problem is solved. (To my shame, it turned out I had an additional instance of neuron in my application folder in addition to the one in my home folder and I used the wrong one. Sorry for that.)

Hey, at least (1) it's a fixable problem, and (2) you discovered & fixed it. Now on to victory!