CompilationError with tesseract-ocr 3.04

[atuyosi]

I'm getting a CompilationError when 'require tesseract-ocr'.

CompilationError: compile error: see logs at /tmp/.ffi-inline-1000/00ac1de4050b632b230475bd71c0dc3a7de45a89.log
from /usr/lib/ruby/gems/2.2.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/compilers/gcc.rb:35:in `compile'

full trace is here, and ffi-inline's error log

Is the latest tesseract-ocr( 3.04) supported?
or any API changed?

There are similar problem bellow.

ruby on rails - Tesseract-ocr gem issue on mac os x - Stack Overflow

OS: Arch Linux
gem

$ gem list tesseract-ocr -d

*** LOCAL GEMS ***

tesseract-ocr (0.1.8)
    Author: meh.
    Homepage: http://github.com/meh/ruby-tesseract-ocr
    License: BSD
    Installed at: /usr/lib/ruby/gems/2.2.0

    A wrapper library to the tesseract-ocr API.

tesseract

$ tesseract -v
tesseract 3.04.00
 leptonica-1.71
  libgif 5.1.0 : libjpeg 8d : libpng 1.6.18 : libtiff 4.0.4 : zlib 1.2.8 : libwebp 0.4.3

ruby

$ ruby -v
ruby 2.2.3p173 (2015-08-18 revision 51636) [x86_64-linux]

Thanks in Advance.

[meh]

Yeah, it looks like they changed quite some stuff, especially regarding output.

It will take some time, in the meantime you can use downgrade or downgrader from the AUR.

[atuyosi]

OK. Thanks.

[McRip]

👍

[acrogenesis]

do you know which stuff changed? perhaps I can help

[meh]

@acrogenesis it looks like they added a TessRenderResult class which is used in place of STRING for ProcessPages.

[cxhartmann]

The changes in the following fork fixed the problem for me with the Tesseract 3.04 baseline: ortutay@74a4042

This also applies to MacOS and Tesseract installed via Homebrew which now defaults to 3.04.

@meh can you share your thoughts on this change

[meh]

@cxhartmann the problem is the Ruby side of things expect process_page to store its value in a STRING*, which is not the case anymore.

With that change it's going to compile, but it's going to segfault or worse as soon as you use anything related to process_page.

[cxhartmann]

@meh Ah I see. So there is more to it. Bummer, but only if you use process_page? I'd have to guess it might be more than just that.

For now I'm reverting to Tesseract v 3.02 and that seems to be working. Now that homebrew points to 3.04 (as of Sept), I went ahead and just brew uninstalled and sucked down the old homebrew formula to do the 3.02 build for me and that seems to be working fine. https://github.com/Homebrew/homebrew/blob/master/Library/Formula/tesseract.rb (check a few revisions back)

[meh]

@cxhartmann yes, and the biggest problem is getting this gem to work with both pre and post 3.04.

[tpendragon]

@meh Any word on supporting 3.04?

[meh]

Haven't had the time to work on it unfortunately, it's on my endless TODO list

[alexhanh]

+1

[noraj]

I just wanted to use easy_captcha_solver ruby gem that requires tesseract-ocr ruby gem. It installed without error but when I try to use it I see that tesseract-ocr is failing to compile.

OS :

$ cat /etc/*-release                                                                                                                                                                                                                        
DISTRIB_ID=ManjaroLinux
DISTRIB_RELEASE=16.08
DISTRIB_CODENAME=Ellada
DISTRIB_DESCRIPTION="Manjaro Linux"
Manjaro Linux
NAME="Manjaro Linux"
ID=manjaro
PRETTY_NAME="Manjaro Linux"
ANSI_COLOR="1;32"
HOME_URL="http://www.manjaro.org/"
SUPPORT_URL="http://www.manjaro.org/"
BUG_REPORT_URL="http://bugs.manjaro.org/"

Gem :

$ gem list tesseract-ocr -d      
*** LOCAL GEMS ***

tesseract-ocr (0.1.8)
    Author: meh.
    Homepage: http://github.com/meh/ruby-tesseract-ocr
    License: BSD
    Installed at: /home/noraj/.gem/ruby/2.3.0

    A wrapper library to the tesseract-ocr API.

tessaract :

$ tesseract -v                                     
tesseract 3.04.01
 leptonica-1.73
  libgif 5.1.2 : libjpeg 8d (libjpeg-turbo 1.4.2) : libpng 1.6.25 : libtiff 4.0.6 : zlib 1.2.8 : libwebp 0.5.1

ruby :

$ ruby -v
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]

It's not clear if I need to import tesseract or tesseract-ocr in my ruby ?

irb(main):002:0> require 'tesseract'
CompilationError: compile error: see logs at /tmp/.ffi-inline-1000/81b6fb2baace695a88ac35bc54fcc39bf2dc1e42.log
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/compilers/gcc.rb:35:in `compile'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders/c.rb:114:in `shared_object'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders.rb:90:in `block in build'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders.rb:87:in `instance_eval'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders.rb:87:in `build'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/inline.rb:54:in `singleton_inline'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/inline.rb:39:in `inline'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:30:in `<module:BaseAPI>'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:27:in `<module:C>'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:25:in `<module:Tesseract>'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:25:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c.rb:89:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/api.rb:26:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract-ocr.rb:35:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract.rb:25:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `rescue in require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:40:in `require'
    from (irb):2
    from /usr/bin/irb:11:in `<main>'
irb(main):003:0> require 'tesseract-ocr'
CompilationError: compile error: see logs at /tmp/.ffi-inline-1000/81b6fb2baace695a88ac35bc54fcc39bf2dc1e42.log
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/compilers/gcc.rb:35:in `compile'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders/c.rb:114:in `shared_object'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders.rb:90:in `block in build'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders.rb:87:in `instance_eval'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/builders.rb:87:in `build'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/inline.rb:54:in `singleton_inline'
    from /home/noraj/.gem/ruby/2.3.0/gems/ffi-inline-0.0.4.3/lib/ffi/inline/inline.rb:39:in `inline'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:30:in `<module:BaseAPI>'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:27:in `<module:C>'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:25:in `<module:Tesseract>'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c/baseapi.rb:25:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/c.rb:89:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract/api.rb:26:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/noraj/.gem/ruby/2.3.0/gems/tesseract-ocr-0.1.8/lib/tesseract-ocr.rb:35:in `<top (required)>'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from (irb):3
    from /usr/bin/irb:11:in `<main>'

It's also not clear if tesseract (distribution package for exemple) is needed for the tesseract-ocr ruby gem ?
It's even not clear if tesseract ruby gem is needed for tesseract-ocr ruby gem ?

HERE is a full ffi-inline error log file.