Linking to libvips.so.42

[nearapogee]

There is a fundamental I am sure I am missing here...

I am trying to install libvips (vips) from homebrew on Ubuntu 20.04 and then link to libvips.so.42 from a gem ruby-vips however it can't find libvips.so.42.

I installed vips with brew install --build-from-source vips.

/home/linuxbrew/.linuxbrew/opt/libvips/lib does contain libvips.so.42:

# ls /home/linuxbrew/.linuxbrew/opt/libvips/lib
girepository-1.0  libvips-cpp.a  libvips-cpp.so  libvips-cpp.so.42  libvips-cpp.so.42.14.2  libvips.a  libvips.so  libvips.so.42  libvips.so.42.14.2  pkgconfig

ldconfig -p | grep vips returns nothing even after an ldconfig (expected)

Installing the gem I get:

LoadError: Could not open library 'vips.so.42': vips.so.42: cannot open shared object file: No such file or directory.
Could not open library 'libvips.so.42': libvips.so.42: cannot open shared object file: No such file or directory

Adding /home/linuxbrew/.linuxbrew/opt/libvips/lib to /etc/ld.so.conf.d/linuxbrew.conf and running ldconfig yields:

# ldconfig -p | grep vips
        libvips.so.42 (libc6,x86-64) => /home/linuxbrew/.linuxbrew/opt/libvips/lib/libvips.so.42
        libvips.so (libc6,x86-64) => /home/linuxbrew/.linuxbrew/opt/libvips/lib/libvips.so
        libvips-cpp.so.42 (libc6,x86-64) => /home/linuxbrew/.linuxbrew/opt/libvips/lib/libvips-cpp.so.42
        libvips-cpp.so (libc6,x86-64) => /home/linuxbrew/.linuxbrew/opt/libvips/lib/libvips-cpp.so

But then on gem install I get:

LoadError: Could not open library 'vips.so.42': vips.so.42: cannot open shared object file: No such file or directory.
Could not open library 'libvips.so.42': /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.29' not found (required by /home/linuxbrew/.linuxbrew/lib/libjxl.so.0.6)

I am confused by the /lib/x86_64-linux-gnu/ directory in there.

Ultimately my question is what needs to be done so I can use the libs compiled by homebrew?

Or is what I am trying do more difficult than just compiling libvips from source myself?

Am I correct in thinking that there is a version conflict because the brewed vips.so.42 is trying to link to an older version of libstdc++ installed by the OS?

Much thanks!

[nearapogee]

Additional:

# find . -name libvips.*
./.linuxbrew/Cellar/vips/8.12.2_1/share/gtk-doc/html/libvips/libvips.devhelp2
./.linuxbrew/Cellar/vips/8.12.2_1/lib/libvips.so.42
./.linuxbrew/Cellar/vips/8.12.2_1/lib/libvips.so.42.14.2
./.linuxbrew/Cellar/vips/8.12.2_1/lib/libvips.so
./.linuxbrew/Cellar/vips/8.12.2_1/lib/libvips.a
./.linuxbrew/lib/libvips.so.42
./.linuxbrew/lib/libvips.so.42.14.2
./.linuxbrew/lib/libvips.so
./.linuxbrew/lib/libvips.a

Adding /home/linuxbrew/.linuxbrew/lib to /etc/ld.so.conf.d/linuxbrew.conf and running ldconfig yields:

# ldconfig -p | grep vips
        libvips.so.42 (libc6,x86-64) => /home/linuxbrew/.linuxbrew/lib/libvips.so.42
        libvips.so (libc6,x86-64) => /home/linuxbrew/.linuxbrew/lib/libvips.so
        libvips-cpp.so.42 (libc6,x86-64) => /home/linuxbrew/.linuxbrew/lib/libvips-cpp.so.42
        libvips-cpp.so (libc6,x86-64) => /home/linuxbrew/.linuxbrew/lib/libvips-cpp.so

But still get this after FFI tries to use the libvips:

LoadError: Could not open library 'vips.so.42': vips.so.42: cannot open shared object file: No such file or directory.
Could not open library 'libvips.so.42': /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.29' not found (required by /home/linuxbrew/.linuxbrew/lib/libjxl.so.0.6)

I'd like to understand this so I can use homebrew for all my backporting needs. ;-)

What am I missing?

[nearapogee]

Adding /home/linuxbrew/.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/ to /etc/ld.so.conf.d/linuxbrew.conf followed by an ldconfig seems to solve it.

# ldconfig -p | grep libstdc
        libstdc++.so.6 (libc6,x86-64) => /home/linuxbrew/.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.so.6
        libstdc++.so.6 (libc6,x86-64) => /lib/x86_64-linux-gnu/libstdc++.so.6
        libstdc++.so (libc6,x86-64) => /home/linuxbrew/.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.so

I discovered this by:

/home/linuxbrew# find . -name libstdc*
./.linuxbrew/Cellar/gcc/11.2.0_3/share/gcc-11/python/libstdcxx
./.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.so.6
./.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.so.6.0.29-gdb.py
./.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.so
./.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.a
./.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++.so.6.0.29
./.linuxbrew/Cellar/gcc/11.2.0_3/lib/gcc/11/libstdc++fs.a

My question here is... will this get me in trouble down the line - i.e. linking to libraries not installed by homebrew?

Thanks for helping me with the fundamentals.

[danielnachun]

The problem here is that vips is built in Homebrew with our GCC 11, and therefore anything which links to vips must also be built with GCC 11. Unfortunately not all Ruby gems allow you to easily override the compiler used for native C/C++/ObjC/Fortran code, but if you are able to do so, then you could just make sure it uses our GCC 11 and it would work.