NOTES FOR UNIX LIKE PLATFORMS ============================= For Unix/POSIX runtime systems on Windows, please see NOTES.WIN. Shared libraries and installation in non-standard locations ----------------------------------------------------------- Binaries on Unix variants expect to find shared libraries in standard locations, such as /usr/lib, /usr/local/lib and some other locations configured in the system (for example /etc/ld.so.conf on some systems). If the libraries are installed in non-standard locations, binaries will not find them and therefore fail to run unless they get a bit of help from a defined RPATH or RUNPATH. This can be applied by adding the appropriate linker flags to the configuration command, such as this (/usr/local/ssl was the default location for OpenSSL installation in versions before 1.1.0): $ ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl \ -Wl,-rpath,/usr/local/ssl/lib Because the actual library location may vary further (for example on multilib installations), there is a convenience variable in Makefile that holds the exact installation directory and that can be used like this: $ ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl \ -Wl,-rpath,'$(LIBRPATH)' On modern systems using GNU ld.so, a better choice may be to use the new dtags, like this: $ ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl \ -Wl,--enable-new-dtags,-rpath,'$(LIBRPATH)' This sets DT_RUNPATH instead of DT_RPATH. DT_RUNPATH is considered after the environment variable LD_LIBRARY_PATH, while DT_RPATH is considered before that environment variable (which means that the values in that environment variable won't matter if the library is found in the paths given by DT_RPATH).