huh? ld can't find library that is in /usr/lib

I'm trying to build dynagraph (a graph layout engine) but the linker can't find one of the libraries and I can't figure out why.

Code:

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g++ -static -g main.o IncrCalledBack.o DuplicateStream.o createConfiguration.o -Lincrface -lincrface -Ldynadag -ldynadag -Lpathplot -lpathplot -Lfdp -lfdp -Lshortspline -lshortspline -Lvoronoi -lvoronoi -Lcommon -ldynagraph -L/usr/lib/graphviz -lagraph -lpathplan -lcdt -lagraph -lboost_thread -pthread -o dynagraph-whole
/usr/bin/ld: cannot find -lagraph
collect2: ld returned 1 exit status
make: *** [dynagraph-whole] Error 1

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The libraries seem to be present:

Code:

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$ ls -l /usr/lib/libagraph*
-rw-r--r-- 1 root root  808 2008-02-08 13:57 /usr/lib/libagraph.la
lrwxrwxrwx 1 root root    18 2008-05-27 16:56 /usr/lib/libagraph.so -> libagraph.so.4.0.0
lrwxrwxrwx 1 root root    18 2008-04-24 17:38 /usr/lib/libagraph.so.4 -> libagraph.so.4.0.0
-rw-r--r-- 1 root root 61336 2008-02-08 13:57 /usr/lib/libagraph.so.4.0.0

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The directory /usr/lib should be in ld's search path (I even tried adding -L/usr/lib just in case). So why is ld complaining? Any pointers or hints on troubleshooting would be much appreciated!

Cheers,
Z.

The liblagraph.so is the shared library. You need the .ar version to link to your code. Usually, those come from a "-devel" variant when you install, e.g. you have "blah.2.9.rpm", and a "blah-devel.2.9.rpm" (rpm is just one of several types of "installable package" - yours may be one of many others).

--
Mats

Quote:

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Originally Posted by matsp

The liblagraph.so is the shared library. You need the .ar version to link to your code. Usually, those come from a "-devel" variant when you install, e.g. you have "blah.2.9.rpm", and a "blah-devel.2.9.rpm" (rpm is just one of several types of "installable package" - yours may be one of many others).

--
Mats

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Thanks for the suggestion Mats. I have the deb package libgraphviz-dev installed:

Code:

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$ dpkg -l libgraphviz*
[..]
ii  libgraphviz-dev        2.16-3ubuntu2          graphviz libs and headers against which to build applications
rc  libgraphviz3            2.12-4ubuntu3          rich set of graph drawing tools
un  libgraphviz3-dev        <none>                  (no description available)
ii  libgraphviz4            2.16-3ubuntu2          rich set of graph drawing tools
un  libgraphviz4-dev        <none>                  (no description available)

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This package supplies the shared libraries:

Code:

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$ dpkg -L libgraphviz-dev | grep agraph
/usr/include/graphviz/agraph.h
/usr/lib/pkgconfig/libagraph.pc
/usr/lib/libagraph.la
/usr/share/man/man3/agraph.3.gz
/usr/lib/libagraph.so

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Could it be that the package is missing the .ar ?

The problem appears to be related to the graphviz packages in Ubuntu 8.10. I installed from the latest stable graphviz sources and the linking problem goes away.

However, I haven't found a satisfactory explanation. The libraries look very similar to those provided by the Ubuntu packages.

Code:

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$ ls -l /usr/local/lib/ | grep agraph
-rwxr-xr-x  1 root root      837 2008-05-28 14:50 libagraph.la
lrwxrwxrwx  1 root root      18 2008-05-28 14:50 libagraph.so -> libagraph.so.4.0.0
lrwxrwxrwx  1 root root      18 2008-05-28 14:50 libagraph.so.4 -> libagraph.so.4.0.0
-rwxr-xr-x  1 root root  254507 2008-05-28 14:50 libagraph.so.4.0.0

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Cheers,
Z.

Are you sure there's no other libagraph file(s) somewhere else?

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Mats

When you pass -lagraph to the linker, it's looking for a file named libagraph.a, no? If you want to statically link with libagraph.la, you have to explicitly pass that name to the linker.