Mise à jour terminée. Pour connaître les apports de la version 13.8.4 par rapport à notre ancienne version vous pouvez lire les "Release Notes" suivantes :

## Compilation

- Design #1335: Remove MOREFEM_CHECK_NAN_AND_INF macro as it is currently too severe.
- Support #1330: std::optional is not yet supported by Apple Clang, and poorly by g++ 7 / libstdc++. So at the moment boost alternative is used; this ticket remains open as Boost is hopefully only a temporary fix.

## Core

- Bug #1334: TimeDependencyPolicy: substitute properly the environment variables.

## Operators

- Profile #1189: In the case of operators for which solution unknown list and test unknown list are identical, storage and computation are no longer duplicated.

## ParameterInstances

- Bug #1332: Solid: improve the error message when an accessor is called for an undefined solid data.

## FormulationSolver

- Bug #1340: Exceptions thrown in functions fed to PETSc Newton mechanism couldn't be caught correctly in external models due to libc++-abi issue, leading to messy error messages at the end of the program. Now the default provided such functions catch internally such exceptions and convert them into a PETSc error code; a macro MOREFEM_NO_TRAP_SNES_EXCEPTION has been added to enable former behaviour.

## Tests

- Design #1333: Introduce in DomainManager a friendship to enable lightweight creation of domains in test.

## CMake

- Support #1341: CMake: propagate properly compilation definitions to external projects.
- Support #1339: CMake: do not use PROJECT_NAME while defining the macro MOREFEM_INSTALL_DIR.
- Support #1329: CMake: reduce the number of Pre cache files.
This tag has no release notes.