This bug can appear in various programs and on various arches, but - I guess - the most common occurence is in imagemagick on amd64:
$ convert abc.png abc.jpg
convert: symbol lookup error:
/usr/lib64/ImageMagick-6.2.8/modules-Q16/coders/png.so: undefined symbol:
Some of the pieces of assembler code in pnggccrd.c fail to build on x86_64. This is known and libpng's configure prevents this sections from being built by passing -DPNG_NO_ASSEMBLER_CODE to gcc. Therefore PNG_ASSEMBLER_CODE_SUPPORTED is not defined in pngconf.h and libpng builds without errors.
The problem is that PNG_NO_ASSEMBLER_CODE is not recorded in pngconf.h or somewhere else. There are some assembler-related functions like png_get_asm_flags in libpng that are only built if the assembler parts are built because they are useless otherwise. Programs (like imagemagick) that use that functions have to test if PNG_ASSEMBLER_CODE_SUPPORTED is defined to assure that they are not used if they are not built into libpng.
But as PNG_NO_ASSEMBLER_CODE is not recorded anywhere PNG_ASSEMBLER_CODE_SUPPORTED is always defined - leading to the kind problems the one I described above is an example for.
I have reported this upstream (sf.net bug 1514938 ), but it doesn't seem like there will be another 1.2-bugfix release.
This bug was discussed in bug 136452 so far, but it doesn't really belong there. The patch attached - which is basically a backport from =libpng-1.4.0beta8 - is the one I originally attached to bug 136452. It is against =libpng-1.2.10, but works for =libpng-1.2.12 too.
Created attachment 90802 [details, diff]
Backported fix from =libpng-1.4.0beta8
you *must* execute autogen.sh because this patch changes Makefile.am and configure.ac
This is now blocking the tracker instead of the "original" imagemagick bug that is already fixed in unstable.
fixed with 1.2.12-r1
*** Bug 140418 has been marked as a duplicate of this bug. ***
Won't be fixed until this gets stable. It breaks stable stuff (such as imagemagick on amd64).
*** Bug 138341 has been marked as a duplicate of this bug. ***
*** Bug 141921 has been marked as a duplicate of this bug. ***
@ppc64 - might be a problem for you as well, please have a look (and remove yourself again if not :)
1.2.12-r1 and a recompile of ImageMagick works for me.
thanks for the info. 1.2.12 works fine on ppc64 (tested with imagemagick). following the stable marking of 1.2.12-r1 also done by other archs though.
all set then
*** Bug 157044 has been marked as a duplicate of this bug. ***