Flutter Linux deployments broken because of missing library

[HankG]

I'm experimenting with doing manual deployments of an app on many platforms including Linux. On the Linux platform the app won't start because it can't find the libobjectbox.so library. Looking at the executable with ldd it looks like the link is being set to a link one directly up from the bundle directory to build/linux/x64/release/_deps/... rather than within the build/linux/x64/release/bundle/libs folder. Ironically the file libobjectbox_flutter_libs_plugin.so is in that proper location so it is only the base library that causes the problem.

Basic info (please complete the following information):

• ObjectBox version: 1.7.1
• Flutter/Dart SDK: Flutter 3.3.10 with Dart 2.18.6
• Null-safety enabled: yes
• Reproducibility: always
• OS: Linux Mint 21 Cinnamon and Ubuntu 22 Budgie
• Device/Emulator: Linux desktop

Steps to reproduce

1. Create a flutter project with the library
2. Build the project on a Linux machine with the command flutter build linux --release
3. Copy the corresponding build bundle directory to a non-build machine
4. Attempt to run the executable

Expected behavior

The program runs without the need for manually copying libraries, setting LD_LIBRARY_PATH etc.

• Did you find any workarounds to prevent the issue?
  This problem can be resolved in the short term by manually adding this to the lib folder and then executing LD_LIBRARY_PATH to explicitly include that folder on the deployed system.

[greenrobot-team]

See the Dart tab at https://docs.objectbox.io/getting-started, specifically the part about "Deploying Dart-native projects".

If that doesn't answer your question, please follow up!

[HankG]

See the Dart tab at https://docs.objectbox.io/getting-started, specifically the part about "Deploying Dart-native projects".

If that doesn't answer your question, please follow up!

This is a Flutter app not a Dart native app. This problem doesn't exist on Mac or Windows just on Linux. It seems on those platforms the build script is correctly placing the objectbox library in the same location as the objectbox flutter libs plugin library. I think that should probably be what happens on Linux as well. Then when the app is linked it looks for it in the nested directory instead of elsewhere on the build system and it "just works" on the end user's machine.

[greenrobot-team]

Sorry, I quickly jumped to Dart native because as you said with Flutter the library is bundled automatically.

I could reproduce this on Ubuntu 22.04 using the relations example. The output of ldd objectbox_demo_relations indeed has the following (after moving the bundle folder into ~/Downloads/obx_demo):

libobjectbox_flutter_libs_plugin.so => /home/<user>/Downloads/obx_demo/./lib/libobjectbox_flutter_libs_plugin.so 
libflutter_linux_gtk.so => /home/<user>/Downloads/obx_demo/./lib/libflutter_linux_gtk.so
libobjectbox.so => /home/<user>/git/objectbox-dart/objectbox/example/flutter/objectbox_demo_relations/build/linux/x64/release/_deps/objectbox-download-src/lib/libobjectbox.so

It appears libobjectbox.so is treated as a globally installed library. Will have to check if flutter_libs/linux/CMakeLists.txt (same for sync_flutter_libs) needs to be updated.

[greenrobot-team]

@HankG I've just released preview version 1.7.2-dev.0 which should resolve this issue by no longer linking the shared library into the built executable. Let me know if this resolves the issue for you as well.

(Note: using flutter pub upgrade will not update to this preview version, manually change the version in your pubspec.yaml instead and run flutter pub get.)

[HankG]

I've confirmed that this is working now. Awesome! Thanks!

[greenrobot-team]

@HankG Thanks!

The fix is now available in the latest stable version 1.7.2.