Help! DOSBox SVN core won't load (but it's fine on my other PC) :-(

Hey guys! I reinstalled Linux Mint 19.3 on my laptop and just installed Retroarch 1.8.6 from the PPA.

I installed all the cores I usually use, and they all work, except DOSBox SVN. When I select it in “Load Core”, nothing happens. When attempting to run a game with it, RA says “failed to open libretro core”.

I have RA running on my desktop PC on the same OS, also from the PPA, and the same core works perfectly on that computer.

I updated all cores to the latest versions on both PCs. What’s happening? How would I even begin to investigate this issue?

I uninstalled the PPA version and installed the RetroArch snap instead. The result is exactly the same.

It makes no sense… All other cores load and run perfectly, just not DOSBox-SVN (and DOSBox Core). And only on this PC! It seems completely arbitrary.

Any input would be really greatly appreciated. I do plan to use this laptop for playing my DOS games. :frowning:

After installing the snap on my desktop PC (where the core worked at first) and uninstalling the PPA version, it’s now not working there either. However, I was able to make a log.

I’m guessing these two lines might shed some light?

[ERROR] Failed to open libretro core: "/home/thebrightside/snap/retroarch/398/.config/retroarch/cores/dosbox_svn_libretro.so"
[ERROR] Error(s): libslang.so.2: cannot open shared object file: No such file or directory

Here’s the full log:

[INFO] RetroArch 1.8.6 (Git 6cf7e57)
[INFO] === Build =======================================
[INFO] CPU Model Name: Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
[INFO] Capabilities:  MMX MMXEXT SSE SSE2 SSE3 SSSE3 SSE4 SSE4.2 AES AVX AVX2
[INFO] Built: May  6 2020
[INFO] Version: 1.8.6
[INFO] Git: 6cf7e57
[INFO] =================================================
[INFO] [Environ]: SET_PIXEL_FORMAT: RGB565.
[INFO] Version of libretro API: 1
[INFO] Compiled against API: 1
[INFO] [Audio]: Set audio input rate to: 30000.00 Hz.
[INFO] [Video]: Video @ fullscreen
[ERROR] [Wayland]: Failed to connect to Wayland server.
[INFO] [GLX]: GLX_EXT_swap_control_tear supported.
[INFO] [GL]: Found GL context: x
[INFO] [GL]: Detecting screen resolution 5760x1440.
[INFO] [GLX]: Window manager is Mutter (Muffin).
[INFO] [GLX]: X = 0, Y = 0, W = 5760, H = 1440.
[INFO] [GLX]: Using windowed fullscreen.
[INFO] [GLX]: Found swap function: glXSwapIntervalEXT.
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [GL]: Vendor: NVIDIA Corporation, Renderer: GeForce GTX 1080 Ti/PCIe/SSE2.
[INFO] [GL]: Version: 4.6.0 NVIDIA 440.82.
[INFO] [GL]: Using resolution 2560x1440
[INFO] [GL]: Default shader backend found: glsl.
[INFO] [Shader driver]: Using GLSL shader backend.
[INFO] [GLSL]: Checking GLSL shader support ...
[WARN] [GL]: Stock GLSL shaders will be used.
[INFO] [GLSL]: Found GLSL vertex shader.
[INFO] [GLSL]: Found GLSL fragment shader.
[INFO] [GLSL]: Linking GLSL program.
[INFO] [GLSL]: Found GLSL vertex shader.
[INFO] [GLSL]: Found GLSL fragment shader.
[INFO] [GLSL]: Linking GLSL program.
[INFO] [GLSL]: Found GLSL vertex shader.
[INFO] [GLSL]: Found GLSL fragment shader.
[INFO] [GLSL]: Linking GLSL program.
[INFO] [GL]: Using 4 textures.
[INFO] [GL]: Loaded 1 program(s).
[INFO] [GL]: Using GL_RGB565 for texture uploads.
[INFO] [udev]: Plugged pad: Afterglow Gamepad for Xbox 360 (3695:531) on port #0.
[INFO] [udev]: Pad #0 (/dev/input/event6) supports force feedback.
[INFO] [udev]: Pad #0 (/dev/input/event6) supports 16 force feedback effects.
[INFO] [Joypad]: Found joypad driver: "udev".
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [DBus]: Suspended screensaver via DBus.
[INFO] [Video]: Found display server: x11
[INFO] [PulseAudio]: Requested 24576 bytes buffer, got 18432.
[INFO] [Menu]: Found menu display driver: "gl".
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Menu]: Found menu display driver: "gl".
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [LED]: LED driver = 'null' 0x56187cf14ea0
[INFO] [MIDI]: Initializing ...
[ERROR] [MIDI]: snd_seq_open failed with error -2.
[ERROR] [MIDI]: Initialization failed (list of input devices unavailable).
[INFO] SRAM will not be saved.
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_history.lpl].
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_music_history.lpl].
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_video_history.lpl].
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_image_history.lpl].
[INFO] Loading favorites file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_favorites.lpl].
[INFO] [GL]: VSync => on
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [GL]: VSync => on
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [PulseAudio]: Pausing.
[ERROR] Failed to open libretro core: "/home/thebrightside/snap/retroarch/398/.config/retroarch/cores/dosbox_svn_libretro.so"
[ERROR] Error(s): libslang.so.2: cannot open shared object file: No such file or directory
[INFO] Using content: /home/thebrightside/snap/retroarch/398/../../../Games/MS-DOS/Bthorne/bthorne.exe.
[INFO] arg #0: retroarch
[INFO] arg #1: /home/thebrightside/snap/retroarch/398/../../../Games/MS-DOS/Bthorne/bthorne.exe
[INFO] arg #2: -c
[INFO] arg #3: /home/thebrightside/snap/retroarch/398/.config/retroarch/retroarch.cfg
[INFO] arg #4: -L
[INFO] arg #5: /home/thebrightside/snap/retroarch/398/.config/retroarch/cores/dosbox_svn_libretro.so
[INFO] arg #6: -v
[INFO] Content ran for a total of: 00 hours, 00 minutes, 00 seconds.
[INFO] Unloading game..
[INFO] Unloading core..
[INFO] Unloading core symbols..
[INFO] [Video]: Does not have enough samples for monitor refresh rate estimation. Requires to run for at least 4096 frames.
[INFO] RetroArch 1.8.6 (Git 6cf7e57)
[INFO] Redirecting save file to "/home/thebrightside/snap/retroarch/398/../../../Games/MS-DOS/Bthorne/bthorne.srm".
[INFO] Redirecting save state to "/home/thebrightside/snap/retroarch/398/../../../Games/MS-DOS/Bthorne/bthorne.state".
[INFO] === Build =======================================
[INFO] CPU Model Name: Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
[INFO] Capabilities:  MMX MMXEXT SSE SSE2 SSE3 SSSE3 SSE4 SSE4.2 AES AVX AVX2
[INFO] Built: May  6 2020
[INFO] Version: 1.8.6
[INFO] Git: 6cf7e57
[INFO] =================================================
[INFO] Loading dynamic libretro core from: "/home/thebrightside/snap/retroarch/398/.config/retroarch/cores/dosbox_svn_libretro.so"
[ERROR] Failed to open libretro core: "/home/thebrightside/snap/retroarch/398/.config/retroarch/cores/dosbox_svn_libretro.so"
Error(s): libslang.so.2: cannot open shared object file: No such file or directory
[INFO] [Environ]: SET_PIXEL_FORMAT: RGB565.
[INFO] Redirecting save file to "/home/thebrightside/snap/retroarch/398/../../../Games/MS-DOS/Bthorne/bthorne.srm".
[INFO] Redirecting save state to "/home/thebrightside/snap/retroarch/398/../../../Games/MS-DOS/Bthorne/bthorne.state".
[INFO] Version of libretro API: 1
[INFO] Compiled against API: 1
[INFO] [Audio]: Set audio input rate to: 30000.00 Hz.
[INFO] [Video]: Video @ fullscreen
[ERROR] [Wayland]: Failed to connect to Wayland server.
[INFO] [GLX]: GLX_EXT_swap_control_tear supported.
[INFO] [GL]: Found GL context: x
[INFO] [GL]: Detecting screen resolution 5760x1440.
[INFO] [GLX]: Window manager is Mutter (Muffin).
[INFO] [GLX]: X = 0, Y = 0, W = 5760, H = 1440.
[INFO] [GLX]: Using windowed fullscreen.
[INFO] [GLX]: Found swap function: glXSwapIntervalEXT.
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [GL]: Vendor: NVIDIA Corporation, Renderer: GeForce GTX 1080 Ti/PCIe/SSE2.
[INFO] [GL]: Version: 4.6.0 NVIDIA 440.82.
[INFO] [GL]: Using resolution 2560x1440
[INFO] [GL]: Default shader backend found: glsl.
[INFO] [Shader driver]: Using GLSL shader backend.
[INFO] [GLSL]: Checking GLSL shader support ...
[WARN] [GL]: Stock GLSL shaders will be used.
[INFO] [GLSL]: Found GLSL vertex shader.
[INFO] [GLSL]: Found GLSL fragment shader.
[INFO] [GLSL]: Linking GLSL program.
[INFO] [GLSL]: Found GLSL vertex shader.
[INFO] [GLSL]: Found GLSL fragment shader.
[INFO] [GLSL]: Linking GLSL program.
[INFO] [GLSL]: Found GLSL vertex shader.
[INFO] [GLSL]: Found GLSL fragment shader.
[INFO] [GLSL]: Linking GLSL program.
[INFO] [GL]: Using 4 textures.
[INFO] [GL]: Loaded 1 program(s).
[INFO] [GL]: Using GL_RGB565 for texture uploads.
[INFO] [udev]: Plugged pad: Afterglow Gamepad for Xbox 360 (3695:531) on port #0.
[INFO] [udev]: Pad #0 (/dev/input/event6) supports force feedback.
[INFO] [udev]: Pad #0 (/dev/input/event6) supports 16 force feedback effects.
[INFO] [Joypad]: Found joypad driver: "udev".
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [DBus]: Suspended screensaver via DBus.
[INFO] [Video]: Found display server: x11
[INFO] [PulseAudio]: Requested 24576 bytes buffer, got 18432.
[INFO] [Menu]: Found menu display driver: "gl".
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[ERROR] Failed to open libretro core: "/home/thebrightside/snap/retroarch/398/.config/retroarch/cores/dosbox_svn_libretro.so"
[ERROR] Error(s): libslang.so.2: cannot open shared object file: No such file or directory
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [Font]: Using font rendering backend: freetype.
[INFO] [LED]: LED driver = 'null' 0x56187cf14ea0
[INFO] [MIDI]: Initializing ...
[ERROR] [MIDI]: snd_seq_open failed with error -2.
[ERROR] [MIDI]: Initialization failed (list of input devices unavailable).
[INFO] SRAM will not be saved.
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_history.lpl].
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_music_history.lpl].
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_video_history.lpl].
[INFO] Loading history file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_image_history.lpl].
[INFO] Loading favorites file: [/home/thebrightside/snap/retroarch/398/.config/retroarch/content_favorites.lpl].
[INFO] [GL]: VSync => on
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [GL]: VSync => on
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [PulseAudio]: Pausing.
[INFO] [PulseAudio]: Unpausing.
[INFO] [GL]: VSync => on
[INFO] [GLX]: glXSwapIntervalEXT(1)
[INFO] [PulseAudio]: Pausing.
[INFO] [PulseAudio]: Unpausing.
[INFO] [config] Saved new config to "/home/thebrightside/snap/retroarch/398/.config/retroarch/retroarch.cfg".
[INFO] Content ran for a total of: 00 hours, 00 minutes, 00 seconds.
[INFO] Unloading game..
[INFO] [PulseAudio]: Pausing.
[INFO] Unloading core..
[INFO] Unloading core symbols..
[INFO] [Video]: Does not have enough samples for monitor refresh rate estimation. Requires to run for at least 4096 frames.
[INFO] [Video]: Does not have enough samples for monitor refresh rate estimation. Requires to run for at least 4096 frames.

Another update.

I checked where the missing libslang.so.2 could come from, but the package that provides it is already installed on my PC:

[email protected]:~$ sudo apt-file search libslang.so.2
libslang2: /lib/x86_64-linux-gnu/libslang.so.2
libslang2: /lib/x86_64-linux-gnu/libslang.so.2.3.1
[email protected]:~$ sudo apt install libslang2
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libslang2 is already the newest version (2.3.1a-3ubuntu1).
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

Partial success though: I was able to fix the issue for the RA PPA version on my laptop PC! Log excerpt:

[ERROR] Failed to open libretro core: "/home/thebrightside/.config/retroarch/cores/dosbox_svn_libretro.so"
[ERROR] Error(s): libSDL_net-1.2.so.0: cannot open shared object file: No such file or directory

I found that that libSDL_net-1.2.so.0 is in the package libsdl-net-1.2. After installing that package, the DOSBox-SVN core runs fine in the PPA version of RetroArch 1.8.6 on my laptop.

Do you guys want me to file a bug report about the core being broken on the Snap build? I could put it up as an Issue on the dosbox-svn GitHub page. I’m guessing the libslang.so.2 needs to come packaged with the Snap, because as I understand, Snaps run in sandboxes and use their own libraries, not the libraries installed on the system?

Can’t you just use DOSBox-core instead? It’s the more modern core and it doesn’t require external dependencies. The -svn core is only useful for things like the PS Vita and such, where dosbox-core doesn’t run.

Hey RealNC! Ohh, I didn’t know the dosbox-core is more modern. I was sure I was unable to run either when I tinkered around with this yesterday.

I just tried on the RA snap on my desktop PC and indeed, the -core core does run, while the -svn doesn’t! Also, both cores run well on the PPA version.

Thanks for your suggestion. I will check this out on my laptop as well!

What’s the best way to keep track of development of the DOSBox core(s)? I completely missed that you guys moved from the -svn to the -core.

There’s not much other than github. Maybe I should start a thread here dedicated to dosbox changes.

That would be totally awesome. In the meantime, I’ve read through the documentation of your dosbox-core and I’ve already enabled MIDI in two games. It rocks!

I noticed one issue though. When I try to run more than one game in the same RA session (e.g. play Blackthorne for a bit, then run Commander Keen 4), RA will segfault.

Video:

Log file:

A workaround is to select “Restart Retroarch” from the main menu before loading another DOS game.

Have you experienced this issue at all?

Hm. This is bad. I’m able to reproduce this. It’s not a crash here though. RetroArch keeps running in the background but without a visible window. When I repeat this 3 times for example, I get 3 stuck, invisible RA processes that need to be killed manually.

Will look into it.

Interesting! I tried on both my PCs this morning, and RetroArch disappears from the System Monitor as soon as it crashes.

Tried with both the Ozone and XMB menus. Both PCs run Linux Mint 19.3.

The problem should be fixed now.

Indeed it is! Thanks, that’s awesome :slight_smile: