Assertion `image_info->signature == 0xabacadabUL' failed.

[sbdmmg]

Hello,

I am trying calibre on my laptop (calibre 0.7.46 on Linux 2.6.35-gentoo-r12, Python 2.6.6, gcc 4.4.4). I installed its binaries using

$ sudo python -c "import urllib2; exec urllib2.urlopen('http://status.calibre-ebook.com/linux_installer').read(); main()"

I can start it and see the "Calibre quick start guide", but when I try to convert even a simple "Lorem ipsum" html file to another format (e.g. epub or mobi) I get the following error:

$ ebook-convert foo.html foo.epub
1% Converting input to HTML...
InputFormatPlugin: HTML Input running
<...>
67% Creating EPUB Output
        Looking for large trees in foo.html...
        No large trees found
Generating default cover
ebook-convert: coders/png.c:2825: ReadPNGImage: Assertion `image_info->signature == 0xabacadabUL' failed.
/usr/bin/ebook-convert: line 9:  1557 Aborted                 $base/bin/ebook-convert "$@"

This does not happen when I add the option "--no-default-epub-cover".
However, any image which is present in the original html seems to trigger this crash.

Thanks for any suggestion you might have, and thank you for writing calibre!
Cheers,

davide

[Manichean]

Does this happen with any document containing images? What format are the images in?

[sbdmmg]

Hello,

it happens even with documents without any image (for example foo.html, attached); the generation of the default cover (which is performed when I don't specify "--no-default-epub-cover") is enough to trigger the problem.
Including an image in the html is just another way in which I can reproduce the crash; I am attaching one of the images that I used to reproduce this issue, but I don't think that the problem is due to this specific file.

Thanks,

davide

[Manichean]

This is one for the devs, I think.

[kovidgoyal]

You have some sort of library conflict on your system that is breaking ImageMagick.

I suggest running with

LD_DEBUG=libs and making sure that png.so and libpng are being loaded from /opt/calibre

And/or try the the calibre ebuild

[sbdmmg]

Thanks for your suggestion.
I tried both the ebuild too; unfortunately that doesn't get to the end of the installation, and for this reason I was trying the binary installation.

Indeed there seems to be an issue with the image magick libraries. I tried to work around this by setting LD_LIBRARY_PATH, but it looks like some of the libraries are still being picked up from the system. (I installed calibre in /usr/local/calibre/calibre/)

$ export LD_LIBRARY_PATH=/usr/local/calibre/calibre/lib:/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders/
$ LD_DEBUG=libs ebook-convert foo.html foo.epub

<...a lot of libraries being loaded from /usr/local/calibre...>

     21083:
        Looking for large trees in foo.html...
        No large trees found
Generating default cover
     21083:     find library=liblcms2.so.2 [0]; searching
     21083:      search path=/usr/local/calibre/calibre/lib:/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders               (LD_LIBRARY_PATH)
     21083:       trying file=/usr/local/calibre/calibre/lib/liblcms2.so.2
     21083:
     21083:     find library=libtiff.so.3 [0]; searching
     21083:      search path=/usr/local/calibre/calibre/lib:/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders               (LD_LIBRARY_PATH)
     21083:       trying file=/usr/local/calibre/calibre/lib/libtiff.so.3
     21083:       trying file=/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders/libtiff.so.3
     21083:      search cache=/etc/ld.so.cache
     21083:       trying file=/usr/lib/libtiff.so.3
     21083:
     21083:
     21083:     calling init: /usr/lib/libtiff.so.3
     21083:
     21083:
     21083:     calling init: /usr/local/calibre/calibre/lib/liblcms2.so.2
     21083:
     21083:
     21083:     calling init: /usr/lib/ImageMagick-6.6.5/modules-Q16/coders/png.so
     21083:
     21083:     /usr/lib/ImageMagick-6.6.5/modules-Q16/coders/png.so: error: symbol lookup error: undefined symbol: png_LTX_RegisterPNGImage (fatal)
     21083:     /usr/lib/ImageMagick-6.6.5/modules-Q16/coders/png.so: error: symbol lookup error: undefined symbol: png_LTX_UnregisterPNGImage (fatal)
ebook-convert: coders/png.c:2825: ReadPNGImage: Assertion `image_info->signature == 0xabacadabUL' failed.
/usr/bin/ebook-convert: line 9: 21083 Aborted                 $base/bin/ebook-convert "$@"
     21080:
     21080:     calling fini: /bin/sh [0]
     21080:
     21080:
     21080:     calling fini: /lib/libncurses.so.5 [0]
     21080:
     21080:
     21080:     calling fini: /lib/libdl.so.2 [0]
     21080:
     21080:
     21080:     calling fini: /lib/libc.so.6 [0]

Thanks for any suggestion you may have.

[kovidgoyal]

See http://www.imagemagick.org/script/resources.php for environment variables to control how image magick is loaded

[sbdmmg]

Thanks a lot.
I see that the library causing the crash seems to be png.so, so I tried to point both MAGICK_CODER_FILTER_PATH and MAGICK_CODER_MODULE_PATH to the directory containing this file.
Unfortunately I must be doing something wrong, since the error is still there.

$ find /usr/local/calibre/ -name png.so
/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders/png.so
$ echo $MAGICK_CODER_FILTER_PATH 
/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/filters/:/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders/
$ echo $MAGICK_CODER_MODULE_PATH
/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/filters/:/usr/local/calibre/calibre/lib/ImageMagick/modules-Q16/coders/

I am not an ImageMagick expert, and this binary installation seems to be as hard as the ebuild...maybe I should try to go back to the ebuild and see if I can get that to work.
Thanks for any suggestion.