media-gfx/digikam-6.4.0 undefined symbol - media-libs/opencv

Goverp · Advocate Joined: 07 Mar 2007 Posts: 2014

I'm getting the following error on my updated digikam:

fedeliallalinea · Posted: Thu Mar 19, 2020 3:09 pm Post subject:

Try to recompile dev-cpp/tbb and media-libs/opencv
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Goverp · Advocate Joined: 07 Mar 2007 Posts: 2014

fedeliallalinea,

I owe you a pint! How did you work out the tbb bit? I'd tried recompiling opencv without success!
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Greybeard

fedeliallalinea · Posted: Fri Mar 20, 2020 1:30 pm Post subject:

Hu · Administrator Joined: 06 Mar 2007 Posts: 21709

c++filt can also be helpful:

fedeliallalinea · Posted: Sat Mar 21, 2020 8:44 am Post subject:

Goverp · Advocate Joined: 07 Mar 2007 Posts: 2014

I'd just assumed the mangled name was crypto-rubbish. That's two things I learnt yesterday, thanks.
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Greybeard

Hu · Administrator Joined: 06 Mar 2007 Posts: 21709

c++filt can be given a symbol to demangle as an argument, or can be run without arguments to demangle each symbol given on stdin. In the example I pasted, I used stdin out of habit. The utility of this depends on the mangled symbol. For a library like tbb, where the authors used a C++ namespace, it works well. Library authors are not required to choose good names, so you might some day see a missing symbol init_algorithms(std::string) or similar. If the missing symbol is too generic, a follow-up Internet search may be required to figure out what library provides it.