Could not open library 'libglib-2.0.so.0.so'

[linkyndy]

Hello,

I've tried using the 2.0.16 version of this gem on Ruby 2.5.5 (combined with libvips 8.8.3 on an Alpine Docker container, if it helps) and I get the following error:

Traceback (most recent call last):
	24: from /usr/local/bin/bundle:22:in `<main>'
	23: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/friendly_errors.rb:124:in `with_friendly_errors'
	22: from /usr/local/bin/bundle:30:in `block in <main>'
	21: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli.rb:18:in `start'
	20: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor/base.rb:466:in `start'
	19: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli.rb:27:in `dispatch'
	18: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor.rb:387:in `dispatch'
	17: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor/invocation.rb:126:in `invoke_command'
	16: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/vendor/thor/lib/thor/command.rb:27:in `run'
	15: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli.rb:494:in `console'
	14: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/cli/console.rb:15:in `run'
	13: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler.rb:114:in `require'
	12: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:65:in `require'
	11: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:65:in `each'
	10: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:76:in `block in require'
	 9: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:76:in `each'
	 8: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:81:in `block (2 levels) in require'
	 7: from /usr/local/lib/ruby/site_ruby/2.5.0/bundler/runtime.rb:81:in `require'
	 6: from /app/vendor/bundle/ruby/2.5.0/gems/ruby-vips-2.0.16/lib/ruby-vips.rb:1:in `<top (required)>'
	 5: from /app/vendor/bundle/ruby/2.5.0/gems/ruby-vips-2.0.16/lib/ruby-vips.rb:1:in `require'
	 4: from /app/vendor/bundle/ruby/2.5.0/gems/ruby-vips-2.0.16/lib/vips.rb:36:in `<top (required)>'
	 3: from /app/vendor/bundle/ruby/2.5.0/gems/ruby-vips-2.0.16/lib/vips.rb:45:in `<module:GLib>'
	 2: from /app/vendor/bundle/ruby/2.5.0/gems/ffi-1.11.1/lib/ffi/library.rb:99:in `ffi_lib'
	 1: from /app/vendor/bundle/ruby/2.5.0/gems/ffi-1.11.1/lib/ffi/library.rb:99:in `map'
/app/vendor/bundle/ruby/2.5.0/gems/ffi-1.11.1/lib/ffi/library.rb:145:in `block in ffi_lib': Could not open library 'glib-2.0.so.0': Error loading shared library glib-2.0.so.0: No such file or directory. (LoadError)
Could not open library 'libglib-2.0.so.0.so': Error loading shared library libglib-2.0.so.0.so: No such file or directory

I assume it has to do with the latest changes with regards to generating libnames.

[jcupitt]

Hello @linkyndy,

Well, that looks bad: libglib-2.0.so.0.so

I'll see if I can reproduce the problem in a docker container.

[jcupitt]

Yes, I see this in a container as well:

https://github.com/jcupitt/docker-builds/blob/master/ruby-vips-alpine/Dockerfile

Here's what seems to be happening:

• ruby-vips wants to open library glib-2.0, API number 0
• on linux, ruby-vips library_name turns this into glib-2.0.so.0
• ffi_lib calls map_library_name to turn this into a platform native name
• this adds a lib prefix to make libglib-2.0.so.0 (the correct name)
• map_library_name then incorrectly adds an extra .so suffix if FFI::Platform::IS_GNU is not true

https://github.com/ffi/ffi/blob/master/lib/ffi/library.rb#L50

So it looks like Alpine is not GNU enough for ffi, I think. Looking at IS_GNU it's:

https://github.com/ffi/ffi/blob/master/lib/ffi/platform.rb#L91

    IS_GNU = defined?(GNU_LIBC)

So I think this is a Ruby ffi bug: they should not add that extra suffix on Alpine.

[jcupitt]

What do you think @linkyndy? We could try opening an issue on ruby ffi. Perhaps they need an IS_MUSL?

[linkyndy]

I tested with both 2.0.15 and 2.0.16 of this gem, using the same setup, and everything is fine with the former. That's why I stopped my investigation here and didn't go to FFI. If you checked more things (thanks for that!) and feel it belongs to FFI, sure, I can pass this along.

[jcupitt]

I think it only worked on Alpine with ruby-vips 2.0.15 if you had the glib-dev package installed.

Without that package, there's no libglib-2.0.so link, and it would have failed to find the library.

[linkyndy]

Both gem versions were tested with the following installed on an Alpine container:

RUN apk add --no-cache --repository http://dl-3.alpinelinux.org/alpine/edge/community/ \
  build-base \
  curl-dev \
  nano \
  libffi-dev \
  vips-dev

So, I would assume the dependencies were the same 🤔

[jcupitt]

vips-dev will have pulled in glib-dev. If you try with just vips I think it'll fail (I think).

[jcupitt]

I made an issue here: ffi/ffi#727

[linkyndy]

Thanks a lot @jcupitt for your very quick action! Looking forward to this being resolved 😊

[jcupitt]

The very helpful @larskanis has changed ffi to hopefully fix this.

I'll close -- please open a new issue if you run into more problems.

[larskanis]

ffi-1.11.2 should fix this issue.