Manually installed audio plugins found, but Nix-built ones not found

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1

Hello dear NixOS community,

There are a number of audio plugins packaged for NixOS. I want to use one: the LV2 plugin drumgizmo. It’s included in my configuration package list, which build successfully, but Reaper does not find it when it rescans for plugins.

My ~/.lv2 folder contains the Pianoteq plugin (built manually) and the drumgizmo plugin (built by Nix):

[jeff@jbb-hp24-oled:~/.lv2]$ ls -l
total 12
lrwxrwxrwx  1 jeff users   60 Dec  8 12:07  drumgizmo -> /nix/store/n0jx8jsabagydbbbmvax4hv9m77ddc0n-drumgizmo-0.9.20
drwxr-xr-x  2 jeff users 4096 Aug 10  2023 'Pianoteq 8.lv2'

I know Reaper is scanning that folder, because when I set the Reaper .lv2 pathlist to empty, it does not find Pianoteq, but when I set it to “~/.lv2;” it does.

I thought maybe there was a permissions problem so I copied everything in the drumgizmo store path to a new folder ~/.lv2/drumgizmo-writeable, ran `chmod -R 777" on all of that stuff, and rescanned again from Reaper. Still no dice.

Any ideas?

A nuance: symlinkJoin in my package list

I didn’t mention this above because it seems likely irrelevant for solving this problem, but I build drumgizmo inside a symlinkJoin expression:

{
  environment.systemPackages =
    with pkgs; [
    ...
    (symlinkJoin {
      name = "jbb-plugins"; # my initials are JBB
      paths = [
        drumgizmo
	...

I first tried symlinking the entire jbb-plugins/ store path into ~/.lv2 and rescanning, but when I do I get the same result – Reaper only finds Pianoteq. That was what led me to try linking directly to the drumgizmo store path in ~/.lv2.

In case it helps: The Pianoteq and drumgizmo folder contents

s[jeff@jbb-hp24-oled:~/.lv2]$ tree drumgizmo-writeable/ Pianoteq\ 8.lv2/
drumgizmo-writeable/
├── bin
│   ├── dgvalidator
│   └── drumgizmo
├── lib
│   └── lv2
│       └── drumgizmo.lv2
│           ├── drumgizmo.so
│           └── manifest.ttl
└── share
    └── man
        └── man1
            ├── dgvalidator.1.gz
            ├── dgvalidator.fr.1.gz
            ├── drumgizmo.1.gz
            └── drumgizmo.fr.1.gz
Pianoteq 8.lv2/
├── dsp.ttl
├── manifest.ttl
├── Pianoteq_8.so
└── ui.ttl

9 directories, 12 files
2

Any specific reason why you symlink this to “~/.lv2”? I have

environment.pathsToLink = [ "/lib/vst2" "/lib/vst3" "/lib/clap" "lib/lv2" ];

in my config and then:

    environment.variables = {
      LV2_PATH = "/run/current-system/sw/lib/lv2";
    };

Which seems to work pretty well.

Regarding Reaper finding one plugin but not the other. Are you in any way mixing Unstable / Stable between Reaper and the plugins? Can you run ldd with each .so-file inside the LV2 folders and post the result? Do other plugin hosts (e.g. carla) have the same issue?

3

Thanks for responding, Polygon! Is your config online? If it helps, here’s mine:

https://github.com/JeffreyBenjaminBrown/nixos-experiments/tree/5751ecde294f8409253762d6ea4ba8eff0786d31/config

That’s a permalink to the latest, still-experimental commit that includes the part of your code that didn’t yield a conflict with musnix for me, described below.

Futzing with paths

musnix already defines LV2_PATH = makePluginPath "lv2";, which yields a conflict when I try using your LV2_PATH = "/run/current-system/sw/lib/lv2";. (It has a bunch of similar definitions:

DSSI_PATH   = makePluginPath "dssi";
LADSPA_PATH = makePluginPath "ladspa";
LV2_PATH    = makePluginPath "lv2";
LXVST_PATH  = makePluginPath "lxvst";
VST_PATH    = makePluginPath "vst";
VST3_PATH   = makePluginPath "vst3";

)

I don’t understand it, but I added your

pathsToLink = [
  "/lib/vst2" "/lib/vst3" "/lib/clap" "lib/lv2" ];

to my config and rebuilt.

When I evaluate LV2_PATH in Bash I see

[jeff@jbb-hp24-oled:~]$ echo $LV2_PATH
/home/jeff/.nix-profile/lib/lv2:/run/current-system/sw/lib/lv2:/etc/profiles/per-user/jeff/lib/lv2:/home/jeff/.lv2

No stable/unstable mixing.

I don’t even know how to mix stable and unstable packages. All my packages are from nixpkgs 24.11.

ldd results

[jeff@jbb-hp24-oled:~/.lv2/drumgizmo/lib/lv2/drumgizmo.lv2]$ ldd drumgizmo.so
        linux-vdso.so.1 (0x00007f7250727000)
        libX11.so.6 => /nix/store/ikjw6a952jd9wn5k06mkj710xzabssr0-libX11-1.8.10/lib/libX11.so.6 (0x00007f725040f000)
        libXext.so.6 => /nix/store/d5y0sl4vwsb9m99r18zh1mx4fw9y70g6-libXext-1.3.6/lib/libXext.so.6 (0x00007f72503fa000)
        libsndfile.so.1 => /nix/store/v3mh7x9nhnicg7mkb1r1xmcjjkpyflr3-libsndfile-1.2.2/lib/libsndfile.so.1 (0x00007f725036d000)
        libpthread.so.0 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libpthread.so.0 (0x00007f7250368000)
        libatomic.so.1 => /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/../lib64/libatomic.so.1 (0x00007f725035b000)
        librt.so.1 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/librt.so.1 (0x00007f7250356000)
        libstdc++.so.6 => /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/../lib64/libstdc++.so.6 (0x00007f7250000000)
        libm.so.6 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libm.so.6 (0x00007f725026f000)
        libc.so.6 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6 (0x00007f724fe07000)
        libgcc_s.so.1 => /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/../lib64/libgcc_s.so.1 (0x00007f724fde2000)
        libxcb.so.1 => /nix/store/w63ks7mg1dsgm2gg302ss70wpq7g0l4d-libxcb-1.17.0/lib/libxcb.so.1 (0x00007f724fdb6000)
        libFLAC.so.12 => /nix/store/9nk7ym5kg8rf3v3rxw7yxfbckk120h99-flac-1.4.3/lib/libFLAC.so.12 (0x00007f724fd34000)
        libvorbis.so.0 => /nix/store/bnl8rhs4324hpzk6ik5c4wnz4dz89smg-libvorbis-1.3.7/lib/libvorbis.so.0 (0x00007f724fcf9000)
        libvorbisenc.so.2 => /nix/store/bnl8rhs4324hpzk6ik5c4wnz4dz89smg-libvorbis-1.3.7/lib/libvorbisenc.so.2 (0x00007f724fc4d000)
        libopus.so.0 => /nix/store/8000ndhxf2ppjw91r3r25dr9yhvjgy8w-libopus-1.5.2/lib/libopus.so.0 (0x00007f724fbe5000)
        libogg.so.0 => /nix/store/j2h0qmkjw72p6nh27ii97r9wq042l4ca-libogg-1.3.5/lib/libogg.so.0 (0x00007f724fbda000)
        libmpg123.so.0 => /nix/store/yv263ja8gcwsi2hfzqf32rsy5qjhz8r7-libmpg123-1.32.8/lib/libmpg123.so.0 (0x00007f724fb7b000)
        libmp3lame.so.0 => /nix/store/qa6xya7klldgfhmjvlspg35xb3srgdqm-lame-3.100-lib/lib/libmp3lame.so.0 (0x00007f724fb01000)
        /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib64/ld-linux-x86-64.so.2 (0x00007f7250729000)
        libXau.so.6 => /nix/store/ighb6h0x1nv14ap2fj0j3bqdn0x3xra4-libXau-1.0.11/lib/libXau.so.6 (0x00007f7250264000)
        libXdmcp.so.6 => /nix/store/8jqc1bpk99jgib12wgpdjmnbndrmg7vz-libXdmcp-1.1.5/lib/libXdmcp.so.6 (0x00007f724faf9000)
        libmvec.so.1 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libmvec.so.1 (0x00007f724fa00000)

[jeff@jbb-hp24-oled:~/.lv2/Pianoteq 8.lv2]$ ldd Pianoteq_8.so
        linux-vdso.so.1 (0x00007f0c45704000)
        librt.so.1 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/librt.so.1 (0x00007f0c456f9000)
        libdl.so.2 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libdl.so.2 (0x00007f0c456f4000)
        libfreetype.so.6 => not found
        libstdc++.so.6 => not found
        libm.so.6 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libm.so.6 (0x00007f0c42b19000)
        libmvec.so.1 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libmvec.so.1 (0x00007f0c42a20000)
        libgcc_s.so.1 => /nix/store/2d5spnl8j5r4n1s4bj1zmra7mwx0f1n8-xgcc-13.3.0-libgcc/lib/libgcc_s.so.1 (0x00007f0c456cd000)
        libpthread.so.0 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libpthread.so.0 (0x00007f0c456c8000)
        libc.so.6 => /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6 (0x00007f0c42827000)
        /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib64/ld-linux-x86-64.so.2 (0x00007f0c45706000)
4

I solved it but don’t understand why.

In Reaper I replaced the singleton “~/.lv2” with everything in LV2_PATH (after replacing each colon with a semicolon, because that’s how Reaper likes it), and then rescanning worked.

I don’t understand why Reaper would find the LV2 plugins from those other paths if it couldn’t in ~/.lv2 after I had symlinked them there.