How to make a binary compatible with different distributions

Question

I need to create an executable that works with as many distributions as possible. I read a lot of information about this and I discovered that there are two ways: static linking and dynamic linking. The first solution avoids bringing with the executable the libraries, but it has some problems with the licenses. The second solution appears the more suitable. With dynamic linking the linker adds to the executable ELF header all the references of the libraries which it needs and the operating system loads these libraries before executing the binary.

The command readelf -d <binary> shows the needed libraries:

Dynamic section at offset 0x149d80 contains 33 entries:
Tag        Type                         Name/Value
0x0000000000000001 (NEEDED)             Shared library: [libopencv_highgui.so.2.4]
0x0000000000000001 (NEEDED)             Shared library: [libopencv_imgproc.so.2.4]
0x0000000000000001 (NEEDED)             Shared library: [libopencv_core.so.2.4]
0x0000000000000001 (NEEDED)             Shared library: [libstdc++.so.6]
0x0000000000000001 (NEEDED)             Shared library: [libm.so.6]
0x0000000000000001 (NEEDED)             Shared library: [libgcc_s.so.1]
0x0000000000000001 (NEEDED)             Shared library: [libpthread.so.0]
0x0000000000000001 (NEEDED)             Shared library: [libc.so.6]
0x000000000000000f (RPATH)              Library rpath: [$ORIGIN/lib]

while the command ldd <binary> shows all the libraries called from my executable:

linux-vdso.so.1 =>  (0x00007fffbb14c000)
libopencv_highgui.so.2.4 => /home/user/./lib/libopencv_highgui.so.2.4 (0x00007f19398d0000)
libopencv_imgproc.so.2.4 => /home/user/./lib/libopencv_imgproc.so.2.4 (0x00007f1939410000)
libopencv_core.so.2.4 => /home/user/./lib/libopencv_core.so.2.4 (0x00007f1938fb7000)
libstdc++.so.6 => /home/user/./lib/libstdc++.so.6 (0x00007f1938cb3000)
libm.so.6 => /home/user/./lib/libm.so.6 (0x00007f19389b7000)
libgcc_s.so.1 => /home/user/./lib/libgcc_s.so.1 (0x00007f19387a0000)
libpthread.so.0 => /home/user/./lib/libpthread.so.0 (0x00007f1938583000)
libc.so.6 => /home/user/./lib/libc.so.6 (0x00007f19381c3000)
libtiff.so.4 => /usr/lib/x86_64-linux-gnu/libtiff.so.4 (0x00007f1937f49000)
libgstreamer-0.10.so.0 => /usr/lib/x86_64-linux-gnu/libgstreamer-0.10.so.0 (0x00007f1937c62000)
libgobject-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007f1937a13000)
libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f193771d000)
libgstapp-0.10.so.0 => /usr/lib/x86_64-linux-gnu/libgstapp-0.10.so.0 (0x00007f1937511000)
libgstvideo-0.10.so.0 => /usr/lib/x86_64-linux-gnu/libgstvideo-0.10.so.0 (0x00007f19372f5000)
libdc1394.so.22 => /usr/lib/x86_64-linux-gnu/libdc1394.so.22 (0x00007f1937081000)
libv4l1.so.0 => /usr/lib/x86_64-linux-gnu/libv4l1.so.0 (0x00007f1936e7b000)
libavcodec.so.53 => /usr/lib/x86_64-linux-gnu/libavcodec.so.53 (0x00007f193606b000)
libavformat.so.53 => /usr/lib/x86_64-linux-gnu/libavformat.so.53 (0x00007f1935d6a000)
libavutil.so.51 => /usr/lib/x86_64-linux-gnu/libavutil.so.51 (0x00007f1935b4a000)
libswscale.so.2 => /usr/lib/x86_64-linux-gnu/libswscale.so.2 (0x00007f1935904000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f19356fb000)
libgomp.so.1 => /usr/lib/x86_64-linux-gnu/libgomp.so.1 (0x00007f19354ec000)
/lib64/ld-linux-x86-64.so.2 (0x00007f1939bca000)
libjpeg.so.8 => /usr/lib/x86_64-linux-gnu/libjpeg.so.8 (0x00007f193529b000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f1935084000)
libgmodule-2.0.so.0 => /usr/lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007f1934e80000)
libxml2.so.2 => /usr/lib/x86_64-linux-gnu/libxml2.so.2 (0x00007f1934b23000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f193491f000)
libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6 (0x00007f1934717000)
libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f19344d9000)
libgstbase-0.10.so.0 => /usr/lib/x86_64-linux-gnu/libgstbase-0.10.so.0 (0x00007f1934286000)
liborc-0.4.so.0 => /usr/lib/x86_64-linux-gnu/liborc-0.4.so.0 (0x00007f193400b000)
libraw1394.so.11 => /usr/lib/x86_64-linux-gnu/libraw1394.so.11 (0x00007f1933dfb000)
libusb-1.0.so.0 => /lib/x86_64-linux-gnu/libusb-1.0.so.0 (0x00007f1933bec000)
libv4l2.so.0 => /usr/lib/x86_64-linux-gnu/libv4l2.so.0 (0x00007f19339e0000)
libvpx.so.1 => /usr/lib/libvpx.so.1 (0x00007f193373a000)
libvorbisenc.so.2 => /usr/lib/x86_64-linux-gnu/libvorbisenc.so.2 (0x00007f193326b000)
libvorbis.so.0 => /usr/lib/x86_64-linux-gnu/libvorbis.so.0 (0x00007f193303f000)
libtheoraenc.so.1 => /usr/lib/x86_64-linux-gnu/libtheoraenc.so.1 (0x00007f1932e01000)
libtheoradec.so.1 => /usr/lib/x86_64-linux-gnu/libtheoradec.so.1 (0x00007f1932be6000)
libspeex.so.1 => /usr/lib/x86_64-linux-gnu/libspeex.so.1 (0x00007f19329cd000)
libschroedinger-1.0.so.0 => /usr/lib/libschroedinger-1.0.so.0 (0x00007f1932719000)
libgsm.so.1 => /usr/lib/libgsm.so.1 (0x00007f193250b000)
libva.so.1 => /usr/lib/x86_64-linux-gnu/libva.so.1 (0x00007f19322f5000)
libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 (0x00007f19320e4000)
libv4lconvert.so.0 => /usr/lib/x86_64-linux-gnu/libv4lconvert.so.0 (0x00007f1931e6f000)
libogg.so.0 => /usr/lib/x86_64-linux-gnu/libogg.so.0 (0x00007f1931c67000)

Now I have used the option of the linker to set RPATH -Wl,-rpath,\$$ORIGIN/lib (http://en.wikipedia.org/wiki/Rpath) and so before the execution the linker looks as the first path the RPATH. This is true if the DT_RUNPATH is not set (https://wiki.debian.org/RpathIssue). On my Ubuntu 12.04 64 bit, if I check with ldd this is correct all the libraries points to the right path. On Debian 7 64 bit, where the openCV libraries are not present, ldd returns

linux-vdso.so.1 =>  (0x00007fffcf157000)
linux-vdso.so.1 =>  (0x00007fffcf157000)
libopencv_highgui.so.2.4 => /home/user/./lib/libopencv_highgui.so.2.4 (0x00007fd15d4a1000)
libopencv_imgproc.so.2.4 => /home/user/./lib/libopencv_imgproc.so.2.4 (0x00007fd15cfe1000)
libopencv_core.so.2.4 => /home/user/./lib/libopencv_core.so.2.4 (0x00007fd15cb88000)
libstdc++.so.6 => /home/user/./lib/libstdc++.so.6 (0x00007fd15c884000)
libm.so.6 => /home/user/./lib/libm.so.6 (0x00007fd15c588000)
libgcc_s.so.1 => /home/user/./lib/libgcc_s.so.1 (0x00007fd15c371000)
libpthread.so.0 => /home/user/./lib/libpthread.so.0 (0x00007fd15c154000)
libc.so.6 => /home/user/./lib/libc.so.6 (0x00007fd15bd94000)
libtiff.so.4 => /home/user/./lib/libtiff.so.4 (0x00007fd15bb2f000)
libgstreamer-0.10.so.0 => /home/user/./lib/libgstreamer-0.10.so.0 (0x00007fd15b848000)
libgobject-2.0.so.0 => /home/user/./lib/libgobject-2.0.so.0 (0x00007fd15b5f9000)
libglib-2.0.so.0 => /home/user/./lib/libglib-2.0.so.0 (0x00007fd15b303000)
libgstapp-0.10.so.0 => /home/user/./lib/libgstapp-0.10.so.0 (0x00007fd15b0f7000)
libgstvideo-0.10.so.0 => /home/user/./lib/libgstvideo-0.10.so.0 (0x00007fd15aedb000)
libdc1394.so.22 => /home/user/./lib/libdc1394.so.22 (0x00007fd15ac67000)
libv4l1.so.0 => /home/user/./lib/libv4l1.so.0 (0x00007fd15aa61000)
libavcodec.so.53 => /home/user/./lib/libavcodec.so.53 (0x00007fd159c51000)
libavformat.so.53 => /home/user/./lib/libavformat.so.53 (0x00007fd159950000)
libavutil.so.51 => /home/user/./lib/libavutil.so.51 (0x00007fd159730000)
libswscale.so.2 => /home/user/./lib/libswscale.so.2 (0x00007fd1594ea000)
librt.so.1 => /home/user/./lib/librt.so.1 (0x00007fd1592e1000)
libgomp.so.1 => /home/user/./lib/libgomp.so.1 (0x00007fd1590d2000)
/lib64/ld-linux-x86-64.so.2 (0x00007fd15d79b000)
libjpeg.so.8 => /home/user/./lib/libjpeg.so.8 (0x00007fd158e81000)
libz.so.1 => /home/user/./lib/libz.so.1 (0x00007fd158c6a000)
libgmodule-2.0.so.0 => /home/user/./lib/libgmodule-2.0.so.0 (0x00007fd158a66000)
libxml2.so.2 => /home/user/./lib/libxml2.so.2 (0x00007fd158709000)
libdl.so.2 => /home/user/./lib/libdl.so.2 (0x00007fd158505000)
libffi.so.6 => /home/user/./lib/libffi.so.6 (0x00007fd1582fd000)
libpcre.so.3 => /home/user/./lib/libpcre.so.3 (0x00007fd1580bf000)
libgstbase-0.10.so.0 => /home/user/./lib/libgstbase-0.10.so.0 (0x00007fd157e6c000)
liborc-0.4.so.0 => /home/user/./lib/liborc-0.4.so.0 (0x00007fd157bf1000)
libraw1394.so.11 => /home/user/./lib/libraw1394.so.11 (0x00007fd1579e1000)
libusb-1.0.so.0 => /home/user/./lib/libusb-1.0.so.0 (0x00007fd1577d2000)
libv4l2.so.0 => /home/user/./lib/libv4l2.so.0 (0x00007fd1575c6000)
libvpx.so.1 => /home/user/./lib/libvpx.so.1 (0x00007fd157320000)
libvorbisenc.so.2 => /home/user/./lib/libvorbisenc.so.2 (0x00007fd156e51000)
libvorbis.so.0 => /home/user/./lib/libvorbis.so.0 (0x00007fd156c25000)
libtheoraenc.so.1 => /home/user/./lib/libtheoraenc.so.1 (0x00007fd1569e7000)
libtheoradec.so.1 => /home/user/./lib/libtheoradec.so.1 (0x00007fd1567cc000)
libspeex.so.1 => /home/user/./lib/libspeex.so.1 (0x00007fd1565b3000)
libschroedinger-1.0.so.0 => /home/user/./lib/libschroedinger-1.0.so.0 (0x00007fd1562ff000)
libgsm.so.1 => /home/user/./lib/libgsm.so.1 (0x00007fd1560f1000)
libva.so.1 => /home/user/./lib/libva.so.1 (0x00007fd155edb000)
libbz2.so.1.0 => /home/user/./lib/libbz2.so.1.0 (0x00007fd155cca000)
libv4lconvert.so.0 => /home/user/./lib/libv4lconvert.so.0 (0x00007fd155a55000)
libogg.so.0 => /home/user/./lib/libogg.so.0 (0x00007fd15584d000)

it seems correct while on openSuse 12.3 64 bit where I installed openCV there are some libraries external to the path $ORIGIN/lib (libogg)

linux-vdso.so.1 =>  (0x00007fff25fff000)
libopencv_highgui.so.2.4 => /home/user/lib/libopencv_highgui.so.2.4 (0x00007feb4a50c000)
libopencv_imgproc.so.2.4 => /home/user/lib/libopencv_imgproc.so.2.4 (0x00007feb4a04c000)
libopencv_core.so.2.4 => /home/user/lib/libopencv_core.so.2.4 (0x00007feb49bf4000)
libstdc++.so.6 => /home/user/lib/libstdc++.so.6 (0x00007feb498f0000)
libm.so.6 => /home/user/lib/libm.so.6 (0x00007feb495f4000)
libgcc_s.so.1 => /home/user/lib/libgcc_s.so.1 (0x00007feb493de000)
libpthread.so.0 => /home/user/lib/libpthread.so.0 (0x00007feb491c1000)
libc.so.6 => /home/user/lib/libc.so.6 (0x00007feb48e01000)
libtiff.so.4 => /home/user/lib/libtiff.so.4 (0x00007feb48b9d000)
libgstreamer-0.10.so.0 => /home/user/lib/libgstreamer-0.10.so.0 (0x00007feb488b6000)
libgobject-2.0.so.0 => /home/user/lib/libgobject-2.0.so.0 (0x00007feb48667000)
libglib-2.0.so.0 => /home/user/lib/libglib-2.0.so.0 (0x00007feb48372000)
libgstapp-0.10.so.0 => /home/user/lib/libgstapp-0.10.so.0 (0x00007feb48166000)
libgstvideo-0.10.so.0 => /home/user/lib/libgstvideo-0.10.so.0 (0x00007feb47f4a000)
libdc1394.so.22 => /home/user/lib/libdc1394.so.22 (0x00007feb47cd7000)
libv4l1.so.0 => /home/user/lib/libv4l1.so.0 (0x00007feb47ad1000)
libavcodec.so.53 => /usr/local/lib/libavcodec.so.53 (0x00007feb46a00000)
libavformat.so.53 => /usr/local/lib/libavformat.so.53 (0x00007feb46702000)
libavutil.so.51 => /usr/local/lib/libavutil.so.51 (0x00007feb464e2000)
libswscale.so.2 => /usr/local/lib/libswscale.so.2 (0x00007feb462af000)
librt.so.1 => /home/user/lib/librt.so.1 (0x00007feb460a7000)
libgomp.so.1 => /home/user/lib/libgomp.so.1 (0x00007feb45e98000)
/lib64/ld-linux-x86-64.so.2 (0x00007feb4a804000)
libjpeg.so.8 => /home/user/lib/libjpeg.so.8 (0x00007feb45c48000)
libz.so.1 => /home/user/lib/libz.so.1 (0x00007feb45a31000)
libgmodule-2.0.so.0 => /home/user/lib/libgmodule-2.0.so.0 (0x00007feb4582d000)
libxml2.so.2 => /home/user/lib/libxml2.so.2 (0x00007feb454d1000)
libdl.so.2 => /home/user/lib/libdl.so.2 (0x00007feb452cd000)
libffi.so.6 => /home/user/lib/libffi.so.6 (0x00007feb450c5000)
libpcre.so.3 => /home/user/lib/libpcre.so.3 (0x00007feb44e88000)
libgstbase-0.10.so.0 => /home/user/lib/libgstbase-0.10.so.0 (0x00007feb44c35000)
liborc-0.4.so.0 => /home/user/lib/liborc-0.4.so.0 (0x00007feb449ba000)
libraw1394.so.11 => /home/user/lib/libraw1394.so.11 (0x00007feb447ab000)
libusb-1.0.so.0 => /home/user/lib/libusb-1.0.so.0 (0x00007feb4459c000)
libv4l2.so.0 => /home/user/lib/libv4l2.so.0 (0x00007feb44390000)
libvo-amrwbenc.so.0 => /usr/local/lib/libvo-amrwbenc.so.0 (0x00007feb44176000)
libvo-aacenc.so.0 => /usr/local/lib/libvo-aacenc.so.0 (0x00007feb43f58000)
libtheoraenc.so.1 => /usr/local/lib/libtheoraenc.so.1 (0x00007feb43d1d000)
libtheoradec.so.1 => /usr/local/lib/libtheoradec.so.1 (0x00007feb43b04000)
libspeex.so.1 => /usr/local/lib/libspeex.so.1 (0x00007feb438ea000)
libopencore-amrwb.so.0 => /usr/local/lib/libopencore-amrwb.so.0 (0x00007feb436d6000)
libopencore-amrnb.so.0 => /usr/local/lib/libopencore-amrnb.so.0 (0x00007feb434ac000)
libmp3lame.so.0 => /usr/local/lib/libmp3lame.so.0 (0x00007feb43224000)
libfaac.so.0 => /usr/local/lib/libfaac.so.0 (0x00007feb43011000)
libv4lconvert.so.0 => /home/user/lib/libv4lconvert.so.0 (0x00007feb42d9c000)
libogg.so.0 => /usr/local/lib/libogg.so.0 (0x00007feb42b95000)

Each library inside $ORIGIN/lib can be linked with other libraries and they can be different from those inside the folder. For instance if I type ldd from Debian 7 I get

./libavformat.so.53: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.14' not found (required by ./libavformat.so.53)
linux-vdso.so.1 =>  (0x00007fff31499000)
libavcodec.so.53 => /usr/lib/x86_64-linux-gnu/libavcodec.so.53 (0x00007f5dfe09b000)
libavutil.so.51 => /usr/lib/x86_64-linux-gnu/libavutil.so.51 (0x00007f5dfde7a000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f5dfdbf7000)
libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 (0x00007f5dfd9e7000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f5dfd7d0000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f5dfd5b3000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f5dfd229000)
libxvidcore.so.4 => /usr/lib/x86_64-linux-gnu/libxvidcore.so.4 (0x00007f5dfcef2000)
libx264.so.123 => /usr/lib/x86_64-linux-gnu/libx264.so.123 (0x00007f5dfcb69000)
libvpx.so.1 => /usr/lib/x86_64-linux-gnu/libvpx.so.1 (0x00007f5dfc8ca000)
libvorbisenc.so.2 => /usr/lib/x86_64-linux-gnu/libvorbisenc.so.2 (0x00007f5dfc3fb000)
libvorbis.so.0 => /usr/lib/x86_64-linux-gnu/libvorbis.so.0 (0x00007f5dfc1cd000)
libtheoraenc.so.1 => /usr/lib/x86_64-linux-gnu/libtheoraenc.so.1 (0x00007f5dfbf8c000)
libtheoradec.so.1 => /usr/lib/x86_64-linux-gnu/libtheoradec.so.1 (0x00007f5dfbd70000)
libspeex.so.1 => /usr/lib/x86_64-linux-gnu/libspeex.so.1 (0x00007f5dfbb57000)
libschroedinger-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libschroedinger-1.0.so.0 (0x00007f5dfb88a000)
libopenjpeg.so.2 => /usr/lib/x86_64-linux-gnu/libopenjpeg.so.2 (0x00007f5dfb668000)
libmp3lame.so.0 => /usr/lib/x86_64-linux-gnu/libmp3lame.so.0 (0x00007f5dfb3dd000)
libgsm.so.1 => /usr/lib/x86_64-linux-gnu/libgsm.so.1 (0x00007f5dfb1d0000)
libdirac_encoder.so.0 => /usr/lib/x86_64-linux-gnu/libdirac_encoder.so.0 (0x00007f5dfaf40000)
libva.so.1 => /usr/lib/x86_64-linux-gnu/libva.so.1 (0x00007f5dfad28000)
/lib64/ld-linux-x86-64.so.2 (0x00007f5dff22e000)
libogg.so.0 => /usr/lib/x86_64-linux-gnu/libogg.so.0 (0x00007f5dfab22000)
liborc-0.4.so.0 => /usr/lib/x86_64-linux-gnu/liborc-0.4.so.0 (0x00007f5dfa8a4000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f5dfa59d000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f5dfa387000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f5dfa182000)

Hence is it possible to get an executable that depends only from the libraries in $ORIGIN/lib? I compiled with Ubuntu 12.04 64 bit, but if I try to execute on Debian 7 64 bit I get segmentation fault of the linker ld-linux-x86-64.so.2 while in openSuse 12.3 64 bit I get

./binary: relocation error: /home/user/lib/libopencv_highgui.so.2.4: symbol avformat_network_init, version LIBAVFORMAT_53 not defined in file libavformat.so.53 with link time reference

ldd libavformat

ldd libavformat.so.53
linux-vdso.so.1 =>  (0x00007fff8c3c5000)
libavcodec.so.53 => /usr/local/lib/libavcodec.so.53 (0x00007f3634b37000)
libavutil.so.51 => /usr/local/lib/libavutil.so.51 (0x00007f3634916000)
libm.so.6 => /lib64/libm.so.6 (0x00007f36346bf000)
libbz2.so.1.0 => not found
libz.so.1 => /lib64/libz.so.1 (0x00007f36344a7000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f3634289000)
libc.so.6 => /lib64/libc.so.6 (0x00007f3633ef9000)
libvo-amrwbenc.so.0 => /usr/local/lib/libvo-amrwbenc.so.0 (0x00007f3633cdf000)
libvo-aacenc.so.0 => /usr/local/lib/libvo-aacenc.so.0 (0x00007f3633ac0000)
libtheoraenc.so.1 => /usr/local/lib/libtheoraenc.so.1 (0x00007f3633885000)
libtheoradec.so.1 => /usr/local/lib/libtheoradec.so.1 (0x00007f363366c000)
libspeex.so.1 => /usr/local/lib/libspeex.so.1 (0x00007f3633451000)
libopencore-amrwb.so.0 => /usr/local/lib/libopencore-amrwb.so.0 (0x00007f363323d000)
libopencore-amrnb.so.0 => /usr/local/lib/libopencore-amrnb.so.0 (0x00007f3633013000)
libmp3lame.so.0 => /usr/local/lib/libmp3lame.so.0 (0x00007f3632d8a000)
libfaac.so.0 => /usr/local/lib/libfaac.so.0 (0x00007f3632b77000)
/lib64/ld-linux-x86-64.so.2 (0x00007f3635f35000)
libogg.so.0 => /usr/local/lib/libogg.so.0 (0x00007f363296f000)

the binary is in /home/user/. Are there other solutions to distribute a binary without source code?

Answer 1

Yikes! That's a phenomenal number of dependencies! You'll have great difficulty making all those dependencies work across a wide variety of distributions, not least because you probably depend quite strictly on the particular version for a good few of those (ie. if you want to link dynamically to OpenCV, then at the least you'll probably only support distributions that ship the same major version).

As you pointed out, you should never ever create a fully static binary (that's only useful in very specific situations, since a statically compiled binary is the least portable). The rules: never statically link in libc (and if you do, it's forbidden to call dlopen). You are allowed to statically link libstdc++, and doing so gives you compatibility over a wider range of distros at the expense of slight binary size increase. libm, libpthread are basically the same rules as libc, and ancient libraries like libz are safe since they have a very stable ABI.

For the rest, you'll want to separate out the tree of dependencies a bit, and try and statically link in the worst of your run-time dependencies, remembering that you have to link in their dependencies too! So if you found you had to statically link in libavcodec, you'd very likely need to ship libspeex too (unless it has a very stable ABI, I don't know about that library in particular).

Regarding the Debian 7 libc problem: that's probably the easiest of your issues to fix. You simply have to compile on the oldest distro you want to support. If you compile on a more recent Ubuntu or Suse release, you'll get a dependency on a newer version of glibc than Debian 7 ships. Doing the compile on the older machine will be fine (it'll run on the newer distros OK).