No GUI in LV2 plugins (official Arch repo)

I installed Ardour and all LV2 plugins I wanted to use from the offical repos like so:

sudo pacman -S ardour zynaddsubfx drumkv1 synthv1

These plugins work as standalone, and I can route MIDI signals through jack to use them, but I can’t open their GUIs inside Ardour when I use them as LV2 plugins.

I have tried using the AUR ardour-git package and also tried compiling from source myself using this guide:

I’ve read that there might be conflicts in the version of gcc that each of these packages are compiled with, or that the “suil” package might be missing, but I have it installed.

This is my config, which I have not altered from the default Arch install:

Build documentation: False
Debuggable build: False
Export all symbols (backtrace): False
Install prefix: /usr
Strict compiler flags: []
Internal Shared Libraries: True
Use External Libraries: False
Library exports hidden: True
Free/Demo copy: False

ALSA DBus Reservation: True
Architecture flags: None
Aubio: True
AudioUnits: False
Build target: x86_64
Canvas Test UI: False
Beatbox test app: False
CoreAudio: False
CoreAudio 10.5 compat: False
Debug RT allocations: False
Debug Symbols: False
Denormal exceptions: False
FLAC: True
FPU optimization: True
Freedesktop files: True
Libjack linking: weak
Libjack metadata: True
Lua Binding Doc: False
LV2 UI embedding: True
LV2 support: True
LV2 extensions: True
LXVST support: True
Mac VST support: False
OGG: True
Phone home: False
Process thread timing: False
Program name: Ardour
Samplerate: True
PT format: True
PTW32 Semaphore: False
Threaded WaveViews: True
Translation: True
Unit tests: False
Windows VST support: False
Wiimote support: False
Windows key: Mod4><Super

PortAudio Backend: False
CoreAudio/Midi Backend: False
ALSA Backend: True
Dummy backend: True
JACK Backend: True

Builstack: -system-
Mac i386 Architecture: False
Mac ppc Architecture: False

C compiler flags: [’-I/build/ardour/src/ardour-5.12’, ‘-D_FORTIFY_SOURCE=2’, ‘-march=x86-64’, ‘-mtune=generic’, ‘-O2’, ‘-pipe’, ‘-fstack-protector-strong’, ‘-fno-plt’, ‘-DHAVE_RF64_RIFF’, ‘-DWAF_BUILD’, ‘-DNDEBUG’, ‘-fshow-column’, ‘-O3’, ‘-fomit-frame-pointer’, ‘-ffast-math’, ‘-fstrength-reduce’, ‘-pipe’, ‘-DARCH_X86’, ‘-mmmx’, ‘-msse’, ‘-mfpmath=sse’, ‘-DUSE_XMMINTRIN’, ‘-DBUILD_SSE_OPTIMIZATIONS’, ‘-DLXVST_64BIT’, ‘-Wall’, ‘-Wpointer-arith’, ‘-Wcast-qual’, ‘-Wcast-align’, ‘-Wno-unused-parameter’, ‘-DBOOST_SYSTEM_NO_DEPRECATED’, ‘-D_ISOC9X_SOURCE’, ‘-D_LARGEFILE64_SOURCE’, ‘-D_FILE_OFFSET_BITS=64’, ‘-DENABLE_NLS’, ‘-DPROGRAM_NAME=“Ardour”’, ‘-DPROGRAM_VERSION=“5”’, ‘-Wstrict-prototypes’, ‘-Wmissing-prototypes’]
C++ compiler flags: [’-I/build/ardour/src/ardour-5.12’, ‘-D_FORTIFY_SOURCE=2’, ‘-march=x86-64’, ‘-mtune=generic’, ‘-O2’, ‘-pipe’, ‘-fstack-protector-strong’, ‘-fno-plt’, ‘-DHAVE_RF64_RIFF’, ‘-DWAF_BUILD’, ‘-DNDEBUG’, ‘-fshow-column’, ‘-O3’, ‘-fomit-frame-pointer’, ‘-ffast-math’, ‘-fstrength-reduce’, ‘-pipe’, ‘-DARCH_X86’, ‘-mmmx’, ‘-msse’, ‘-mfpmath=sse’, ‘-DUSE_XMMINTRIN’, ‘-DBUILD_SSE_OPTIMIZATIONS’, ‘-DLXVST_64BIT’, ‘-Wall’, ‘-Wpointer-arith’, ‘-Wcast-qual’, ‘-Wcast-align’, ‘-Wno-unused-parameter’, ‘-DBOOST_SYSTEM_NO_DEPRECATED’, ‘-D_ISOC9X_SOURCE’, ‘-D_LARGEFILE64_SOURCE’, ‘-D_FILE_OFFSET_BITS=64’, ‘-DENABLE_NLS’, ‘-DPROGRAM_NAME=“Ardour”’, ‘-DPROGRAM_VERSION=“5”’, ‘-std=c++11’, ‘-DBOOST_NO_AUTO_PTR’, ‘-Woverloaded-virtual’, ‘-Wno-unused-local-typedefs’, ‘-D__STDC_LIMIT_MACROS’, ‘-D__STDC_FORMAT_MACROS’, ‘-DCANVAS_COMPATIBILITY’, ‘-DCANVAS_DEBUG’]
Linker flags: [’-Wl,-O1,–sort-common,–as-needed,-z,relro,-z,now’, ‘-Wl,-O1,–sort-common,–as-needed,-z,relro,-z,now’]

The Ardour version in question is 5.12.0, but also applies to 6.*

And there are no errors in the log

We do not and cannot support self-builds or Linux distribution builds If this issue does not occur with the official build from (which I am fairly sure it does not), then it simply means that your build environment and/or process are incorrect. You may be using the wrong compiler or the wrong version of the LV2 libraries with respect to these plugins, which may be the correct version with respect to everything else.

Thanks for responding @paul, now I became a subscriber and installed the official build, but the problem persists. With drumkv1, synthv1 and zynaddsubfx all built from the official source.

When running ardour directly from commandline, I get this error when trying to open synthv and drumkv1:
suil error: Unable to open UI library /usr/lib/lv2/synthv1.lv2/ (/usr/lib/ undefined symbol: hb_font_funcs_set_nominal_glyph_func)

And with zynaddsubfx:
(ardour-5.12.0:31300): Gdk-CRITICAL **: IA__gdk_window_get_origin: assertion ‘GDK_IS_WINDOW (window)’ failed

Correction: ZynAddSubFX works, if you get the latest from GIT, so it’s just the suil problem now

This just means you’re building the plugins with the wrong build stack. Most likely SUIL was built against the wrong version of Qt or something like that.

Yeah, I suspected as much. It was just not apparent in the Arch versions. I will try to fix that and post the solution in the Arch forums instead.

Thanks for taking the time to respond, and thanks for this amazing software. The work you do is invaluable!