gnu linker: executable cannot find a versioned shared library

[shureg]

Hi

I have a c++ project in which I compile a shared library and then link an executable against it. This used to work fine for me

so, i have a shared library, let's say "libmylib.so",, created with

g++ -shared -Wl,-soname,libmylib.so -o libmylib.so [other otpions]

and it is located in /home/user/project/lib/c++

then i have an executable in [project-path]/cmd/c++ (let's call it "test"), which is linked against this library as

g++ -Wl,-rpath=/home/user/project/lib/c++ -o test -lmylib -L /home/user/project/lib/c++ [other options]

and this all works fine, ldd shows that the executable is able to locate all libraries and it runs as it is supposed to.

Recently, I decided to introduce version numbering to my project. So if the version number is 1.2.3 the library linking command now is

g++ -shared -Wl,-soname,libmylib.so.1 -o libmylib.so.1.2.3 [other options]

followed by

ln -sfv libmylib.so.1.2.3 libmylib.so

creating a convenience symbolic link. this is all still in /home/user/project/lib/c++

running the same executable linking command for the "test" executable as above succeeds, but ldd shows that libmylib.so.1 cannot be found by the executable.

I ran readelf on the library, and it shows that the soname field is set correctly to libmylib.so.1. I also ran readelf on the executable and found that rpath is set correctly to /home/user/project/lib/c++.

I really don't know what to do now. I have had my share of pain when I was working out how the whole dynamic linking system works before, but this is something I cannot understand.

Any help would be greatly appreciated

[gerard4143]

This is probably knit-picking but is this line correct "libmylib.so -o libmylib.so". Just a posting typo?

g++ -shared -Wl,-soname,libmylib.so -o libmylib.so [other otpions]

[shureg]

This is probably knit-picking but is this line correct "libmylib.so -o libmylib.so". Just a posting typo?

g++ -shared -Wl,-soname,libmylib.so -o libmylib.so [other otpions]

I don't think that's a typo, that's how my linking stage always runs. What's wrong with it?

[drl]

Hi.

A long shot: I notice that you are using

-Wl,-soname,libmylib.so.1

man ld says that the form for supplying the soname is

-soname=name

not with a comma, but I have not tried either one personally ... cheers, drl