Hi, this is my first post. Started a couple of months ago studying PD. I'm using it on a Windows desktop and now also on a Linux based laptop. I've installed release 0.52 on both OS, with some external libraries. The object [envgen] of ggee works perfectly under Windows. Nothing to do with LinuxMint. I've the error message
"priority 6 scheduling failed; running at normal priority envgen 200 140 1 0 ... couldn't create".
I've set the correct path in preference. The library is present but it seems PD cant't find envgen when run in Linux.
Any help? What I'm doing wrong?
Thanks a lot

@bobpell I am only an occasional Linux user. It seems strange as the error suggests problems with the OS audio setup/permissions........ but [envgen] is a control rate object.
This might help...... https://lists.puredata.info/pipermail/pd-list/2015-04/109949.html
Or.... https://www.reddit.com/r/puredata/comments/88uwyo/installing_pd_for_linux_mint_18/
There were other threads found by a search for "priority 6 scheduling failed; running at normal priority" that solved the problem by giving Pd root permissions.
David.

@bobpell The priority 6 fail probably happened at startup, I bet you opened pd by opening the patch from your filemanager? This just means you do not get real time audio and there will be a slight delay, this may or may not be an issue for you but almost certainly not the issue with [envgen]. Does [envgen] work if you call it with its full name including library name, [ggee/envgen]? If so than the path is wrong but the ggee library is properly installed. Do other objects from ggee work? If not than either ggee is not installed, install failed or it is not in pd's path and the path to ggee is wrong; if other objects from ggee do work than it means [envgen] is at fault, try reinstalling the library and if that does not work try a different version of the library. Do any other externals work? if no than it is a path issue. If you installed the library through LinuxMint's package manager it could just be a faulty package, install it with deken and see what happens.

[envgen] works on linux for me.

Thanks to all, herafter some comments.

If I run PD as root, "sudo puredata", the message 'priority 6 scheduling failed; running at normal priority' disappears. By the way, even if I opend directly the patch, so with the above error message, everything related to audio seems OK. So that's good, even if not so clear to me what happen...

[envgen] issue
Does [envgen] work if you call it with its full name including library name, [ggee/envgen]? -> No, it is not recognized (dashed box, not continuos line, for the object appears in the canvas)
Do other objects from ggee work? -> No, same dashed box
Do any other externals work? -> not fully clear, for instance the object [counter] that should be part of cyclone works, other object tried not
Path are set in the correct way, and is not clear to me what to do to install library with Deken.

I'm getting lost, what disappoints me is that on Windows I got no issue, but I'm trying to switch to Linux...

Update.

Removed and reinstalled all the libraries in a new folder: everything seems to work!

Concerning the priority 6 message, I guess you're not included in the audio group. In a terminal type grep audio /etc/group. If you see your user name, then you're there. If you don't, you'll need to add yourself to the audio group. In this case type usermod -a -G audio username. Obviously, change "username" for your actual username.

@alexandros: done, after adding myusrn to the audio group I get
$ grep audio /etc/group
audio29:pulse,myusrn

but priority 6 message is still present

@bobpell Your user will not be able to use the new privileges which being in the audio group gives you until the next time you login, so logout and give it a go if you did not do that already.

@oid unfortunately priority 6... still present after restart. As told, if I run from terminal "sudo puredata", no error/warning message. Can't understand, but I guess it's a problem of my Linux knowledge, not of Puredata

Then you also need to edit either /etc/security/limits.conf or /etc/security/limits.d/audio.conf/ and put these lines at the end:

@audio - rtprio 90       # maximum realtime priority
@audio - memlock unlimited  # maximum locked-in-memory address space (KB)

The comments are not necessary. You can also add this line:

@audio   -  nice      -19

In my system though I've commented it out, I guess I don't need it. This tells the system that Pd should not be nice, and not let other programs have priority.

@bobpell You can check in /etc/security for limits.conf or limits.d/, grep limits.conf/the files in limits.d/ for audio, grep audio limits.conf or grep audio limits.d/*, you should have

@audio   -  rtprio     95
@audio   -  memlock    unlimited

If you have them but the settings for rtpro or memlock are different, than change them to 95 and unlimited. If you do not have anything for audio then if you have limits.conf, add the lines, if you have limits.d/ then add the file audio.conf with those lines and restart. If you do have those or adding them does not work than it is a quirk of LinuxMint and you will have to ask in a LinuxMint forum how to set it up or wait for someone more familiar with LinuxMint to show up. LinuxMint is Ubuntu based so this should already be setup and just adding your user to the audio group should work, but LinuxMint may have decided to change this and you will need to ask people well versed in the distro or do some searching to find what you need to do. One thing you can do is install the Ubuntu Studio package, but that is a great deal of software so somewhat overkill.

Edit: looks like I missed an update and duplicated a response, either of our numbers will work. Regarding the niceness line, from what I understand that is a hold over from bygone days and not needed on modern systems, does not hurt to have it but it does not actually accomplish anything.

@alexandros & @oid, in my file /etc/security/limits.conf there were no one of the two lines suggested. So I added them
@audio - rtprio 90 # maximum realtime priority
@audio - memlock unlimited # maximum locked-in-memory address space (KB)

and...
the warning on priority 6 disappeared!
Something magic should be happened
Thanks a lot

This is no magic. You're just telling your system to give a high priority to the audio group (and Pd is an application of that group), and you have added your self to that group, so when YOU launch Pd, you can get the priority Pd asks for.