3.0 KiB
Filesystem Hierarchy Standard Note
In the FHS, /{,s}bin may be a symlink to /usr/{,s}bin and
/lib{,64} may be a symlink to /usr/lib{,64}.
Many modern Linux distributions do in fact implement those directories as symbolic links.
For an RPM .spec file to truly be portable, it can not assume that
those directories are symbolic links and binaries/libraries that belong
within /bin, /sbin, /lib, and /lib64 when they are not symbolic
links should be installed in those directories and not under the /usr
prefix.
For binaries within /{,s}bin, any shared libraries they link against
must be installed within /lib{,64} so that the binary will work in
the event /usr is a separate partition that is not mounted.
Shared Library Packaging
For the shared libraries installed within /lib, I am choosing to put
the developer libfoo.so symbolic link and (if packaged) the developer
libfoo.a static library within /usr/lib even though the shared
library itself is within /lib and not under the /usr prefix. Those
files are not needed in the event /usr is not available.
With a very few exceptions (e.g. libgcc_s and libstdc++ from gcc)
the way I do this is to pass
--libdir=/%{_lib}
to the configure script.
That does result in the shared library being placed within /lib
but usually it also results in the pkgconfig directory also being
placed in /lib along with foolib.so and (if built) foolib.a.
Furthermore, the foolib.pc points to /lib for linking, which
technically is correct if that is where the foolib.so and foolib.a
files are located. However I do not want them in /lib.
In a very few cases, the resulting Makefile is smart enough to do
what I want (put foolib.so in /usr/lib and foo.pc in
/usr/lib/pkgconfig correctly configured) but usually I do have to
manually adjust the install.
An example from the zlib.spec file:
install -m755 -d %{buildroot}%{_libdir}
sed -i 's?libdir=.*?libdir=%{_libdir}?' %{buildroot}/%{_lib}/pkgconfig/zlib.pc
mv %{buildroot}/%{_lib}/pkgconfig %{buildroot}%{_libdir}/
rm -f %{buildroot}/%{_lib}/libz.so
ln -s ../../%{_lib}/libz.so.1.2.13 %{buildroot}%{_libdir}/libz.so
# just in case we ever package the static library
mv %{buildroot}/%{_lib}/libz.a %{buildroot}%{_libdir}/
The install commands creates /usr/lib, the sed command fixes the
zlib.pc file and then the pkgconfig directory is put in the proper
place.
The original /lib/libz.so symbolic link is deleted, and a new one is
created within /usr/lib that points to the actual library that is
still within /lib.
Even though I am not currently packaging the libz.a static library,
it is moved into /usr/lib just in case there ever arises a legitimate
use case to package the static library.
Within the %files devel section, I exclude it from being packages:
%exclude %{_libdir}/libz.a
Most shared libraries belong in /usr/lib and this adjustment is not
necessary.