"cannot open shared object file," but it exists

Question

I'm having trouble finding why this library (matio) isn't working for me. In my Makefile I have this:

LIBS += -L/home/brian/.../matio-1.5.6/src/.libs/ -lmatio

When I attempt to run my code (links fine) I get this error:

error while loading shared libraries: libmatio.so.4: cannot open shared object file: No such file or directory

libmatio.so.4 exists in the directory specified by the -L flag.

I built the library and it seems to go through make check with only a handful writing errors (which is fine as I only need it for reading).

Things I've tried:

Specifying the name (i.e. -l:libmatio.so.4.0.2)
Adding the path to LD_LIBRARY_PATH
Adding the path as a line in /etc/ld.so.conf and run sudo ldconfig
Adding a new file in /etc/ld.so.conf.d with the path and run sudo ldconfig

(When I run ldconfig -p | grep matio nothing returns. Am I doing something wrong with ldconfig?)

I've gotten it to run with libmatio.a, but still don't know why the .so won't work. — brian, Mar 18 '16 at 20:35
I just used the workaround mentioned above. The answer below I'm guessing is pointing to the solution, but I never found it. — brian, Oct 01 '19 at 20:57

score 8 · Answer 1 · answered Mar 10 '16 at 22:46

8

The error is actually telling you "no compatible library with that name exists in the library cache", not "no file with that filename exists on disk".

So, confusingly, this can happen when the shared object file is in the wrong format.

Ensure that it was built for the right platform by the right compiler! You can have a look with file and verify that the dynamic link is failing using ldd on your executable.

answered Mar 10 '16 at 22:46

Lightness Races in Orbit

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I built the library, and as far as I can tell it was done correctly. `ldd` shows: `libmatio.so.4 => not found.` Any tips on how to examine what's wrong with it? – brian Mar 10 '16 at 23:08
@brian: How are your file permissions looking? – Lightness Races in Orbit Mar 10 '16 at 23:27
@brian: Yeah but you're missing something so why not show us what the file permissions are we can tell _you_ whether they're correct :P – Lightness Races in Orbit Mar 11 '16 at 00:29
Right, `-rwxrwxr-x 1 brian brian 934782 Mar 9 11:30 libmatio.so.4.0.2` – brian Mar 11 '16 at 00:39
Are your (possible) library version symlinks correct? What if you rename your library to libmatio.so without any version identifiers and link to that? – juzzlin Mar 11 '16 at 18:44

"cannot open shared object file," but it exists

1 Answers1