If you installed preCICE in a custom prefix, then you still need to make it discoverable by the system.

The preCICE library needs to be discoverable in various ways:

  1. The location of headers must be available during compilation. Compilers use hints from CPATH if no extra compilation flags were passed to them using -I.
  2. The shared library must be available during linking and execution. The dynamic linker uses hints from LD_LIBRARY_PATH (DYLD_LIBRARY_PATH on macOS).
  3. The preCICE executables must be in PATH (optional, only for additional tools).

As this setup can become tedious to maintain, there are some tools that expose the above details. However, they also need to find preCICE in some way:

  • pkg-config and pkgconf use PKG_CONFIG_PATH to search for additional .pc files.
  • CMake uses CMAKE_PREFIX_PATH for additional installation prefixes. Alternatively, one can specify the location of the preCICE CMake configuration file using precice_DIR.

Using the shell

If you are using a Unix-like system, you are using a shell, which offers an easy and straightforward way to make preCICE discoverable.

Let PRECICE_PREFIX be the installation prefix chosen during the preparation step. Then add the following to your .profile (for bash) or .zshrc (for zsh).

# set this to your selected installation prefix
PRECICE_PREFIX="${HOME}/software/prefix"

export PATH="${PRECICE_PREFIX}/bin:${PATH}"
export CPATH="${PRECICE_PREFIX}/include${CPATH:+:$CPATH}"
export LD_LIBRARY_PATH="${PRECICE_PREFIX}/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
export PKG_CONFIG_PATH="${PRECICE_PREFIX}/lib/pkgconfig${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
export CMAKE_PREFIX_PATH="${PRECICE_PREFIX}${CMAKE_PREFIX_PATH:+:$CMAKE_PREFIX_PATH}"

After adding these variables, start a new session (open a new terminal or log out and in again).

Using systemd environment.d

An alternative to the above system is to set these variables in the shell-agnostic environment.d.

Create the directory if it does not yet exist:

mkdir -p ~/.config/environment.d/

Let PRECICE_PREFIX be the installation prefix chosen during the preparation step. Then create a file ~/.config/environment.d/99-precice.conf with the content:

# set this to your selected installation prefix
PRECICE_PREFIX="${HOME}/software/prefix"

PATH="${PRECICE_PREFIX}/bin:${PATH}"
CPATH="${PRECICE_PREFIX}/include${CPATH:+:$CPATH}"
LD_LIBRARY_PATH="${PRECICE_PREFIX}/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
PKG_CONFIG_PATH="${PRECICE_PREFIX}/lib/pkgconfig${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
CMAKE_PREFIX_PATH="${PRECICE_PREFIX}${CMAKE_PREFIX_PATH:+:$CMAKE_PREFIX_PATH}"

After adding the file, log out and in again. Opening a new terminal will not be sufficient. Verify the changes by listing the loaded environment in a new terminal:

systemctl show-environment

Using directly from the binary directory

It may not always be practical to reinstall preCICE repeatedly. This is especially the case for simultaneous development of preCICE and an adapter or while profiling the internals.

This method is discouraged as file layouts are fundamentally different, and we make no guarantees on keeping them consistent across releases. Hence, the only reliable methods for using preCICE from the binary directory require pkg-config or CMake. If your adapter or solver isn’t using one of these methods, we strongly suggest installing preCICE to a prefix or porting the adapter to pkg-config or CMake.

First, extend LD_LIBRARY_PATH with the binary directory if you don’t plan to use rpath (which CMake does by default). For pkg-config users, extend PKG_CONFIG_PATH with the binary directory. For CMake users, either set the environment variable precice_DIR to the binary directory before calling CMake or pass it as a CMake variable during configuration.

# Only for using preCICE directly from the build directory
# (as of preCICE v3.4.0 - later versions might differ).

PRECICE_BUILD="/path/to/precice/build"
PATH="${PRECICE_BUILD}:${PATH}"
LD_LIBRARY_PATH="${PRECICE_BUILD}${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"
PKG_CONFIG_PATH="${PRECICE_BUILD}${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
precice_DIR="${PRECICE_BUILD}"

Verify your installation

First, run:

precice-version

If the binary precice-version cannot be found, then PATH is incorrect. If the library libprecice.so cannot be found, then LD_LIBRARY_PATH is incorrect. If the displayed version differs from the version you expect, then you have multiple conflicting preCICE installations on your system.

Next, run:

pkg-config --modversion libprecice

If libprecice wasn’t found, then your PKG_CONFIG_PATH is incorrect. If the displayed version differs from the version you expect, then you have multiple conflicting preCICE installations on your system.

At this point, check whether the installation step was successful and whether the used installation prefix contains folders bin, lib, and include.

Next steps

This concludes the preCICE installation for custom prefixes. You should now have a working preCICE installation on your system.

To use preCICE in your project, see the page Linking to preCICE.