FMU Export of Multibody Models crash

[julius.martensen@…]

I can not simulate any FMU exported from OMEdit containing parts of the Multibody Library. This is limited to FMUs generated in Ubuntu; models exported in windows work.

A minimal output of the FMUChecker shows the error:

[FATAL][FMICAPI] Could not load the DLL: /media/jmartensen/Data/general/test/fmu_test/fmucktmpwPvnKY/binaries/linux64/Modelica_Mechanics_MultiBody_Examples_Elementary_DoublePendulum.so: undefined symbol: mmc_mk_modelica_array
[FATAL][FMUCHK] Could not create the DLL loading mechanism(C-API) for ME.
[FATAL][FMICAPI] Could not load the DLL: /media/jmartensen/Data/general/test/fmu_test/fmucktmpwPvnKY/binaries/linux64/Modelica_Mechanics_MultiBody_Examples_Elementary_DoublePendulum.so: undefined symbol: mmc_mk_modelica_array
[FATAL][FMUCHK] Could not create the DLL loading mechanism(C-API) for CoSimulation.
FMU check summary:
FMU reported:
	0 warning(s) and error(s)
Checker reported:
	Warnings and non-critical errors were ignored (log level: FATAL)
	4 Fatal error(s) occurred during processing

I tried FMI 1.0 / 2.0 with different linking options. None seems to work.

[Francesco Casella]

Even though most people use FMI under Windows, this seems like a fairly critical issue, particularly if this used to work in previous versions.

@julius.martensen, can you check whether this worked with the 1.12.0 stable release?

[Martin Sjölund]

The same error would occur under Windows unless shipping Boehm GC together with the FMU. 1.13 nightlies catch the error for statically linked FMUs:

/tmp/Modelica_Mechanics_MultiBody_Examples_Elementary_DoublePendulum.fmutmp/sources/Modelica_Mechanics_MultiBody_Examples_Elementary_DoublePendulum_functions.c:147: undefined reference to `mmc_mk_modelica_array'

Fixing the problem would be trivial here since the function pointers actually are unused and don't need to be generated. But I suppose it's better to fix the underlying error...

[Martin Sjölund]

​https://github.com/OpenModelica/OMCompiler/pull/2393

[julius.martensen@…]

Replying to casella:

Even though most people use FMI under Windows, this seems like a fairly critical issue, particularly if this used to work in previous versions.

@julius.martensen, can you check whether this worked with the 1.12.0 stable release?

Thanks for the quick response!

The error occured also using 1.12.0 stable.

[Francesco Casella]

@julius.martensen, ​PR #2393 was merged into master. Please check with tomorrow's nightly build (or right away if you want to recompile omc from sources) if the problem is fixed and close the ticket in that case.

[Martin Sjölund]

I believe this should probably be merged into 1.12 maintenance as well...

[julius.martensen@…]

Works like a charm!

Thanks!

[Francesco Casella]

Are we actually planning a 1.12.1 maintenance release?

[Martin Sjölund]

I continuously build the 1.12 branch for the Linux users... We really should have a 1.12.1 official release though: the fixes are mostly for the GUI: ​https://github.com/OpenModelica/OMCompiler/compare/v1.12.0...maintenance/v1.12 (Adeel also has some fixes in OMEdit that should be merged into the maintenance release)

[Martin Sjölund]

Fixed in ​https://github.com/OpenModelica/OMCompiler/pull/2397

[Francesco Casella]

Can you bring 1.12.1 up at the next devmeeting?