Installation problems for tetgen on linux machine

[annegehrke]

The following error message appeared when I tried to compile UG4 with tetgen (the path to tetgen is correct) on a linux machine:

[ 88%] Linking CXX shared library ../../lib/libug4.so
CMakeFiles/ug4.dir/ugbase/bindings/lua/externals/lua/loslib.c.o: In function `os_tmpname':
loslib.c:(.text+0x21d): warning: the use of `tmpnam' is dangerous, better use `mkstemp'
/usr/bin/ld: ../../tools/tetgen/libtet.a(predicates.o): relocation R_X86_64_PC32 against symbol `_Z6dstored' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value
collect2: error: ld returned 1 exit status
ugcore/CMakeFiles/ug4.dir/build.make:11208: die Regel für Ziel „../lib/libug4.so“ scheiterte
make[2]: *** [../lib/libug4.so] Fehler 1
CMakeFiles/Makefile2:105: die Regel für Ziel „ugcore/CMakeFiles/ug4.dir/all“ scheiterte
make[1]: *** [ugcore/CMakeFiles/ug4.dir/all] Fehler 2
Makefile:83: die Regel für Ziel „all“ scheiterte
make: *** [all] Fehler 2

Does anyone have an idea what went wrong?

[stephanmg]

Did you recompile with -fPIC? (position-independent code)

[mastep84]

Yes, we have tried that already. Unfortunately, the above error remains.

[stephanmg]

Did you use c++filt do demangle the name? It loooks like it is dstore(double). Can you compile tetgen standalone?!

Also much more details are required about the toolchain and the operating system.

[mastep84]

That's a good point. @annegehrke, could you elaborate on that? Also you could try the suggestion by @stephanmg, typing

echo _Z6dstored | c++filt -s

after you get the build error message. Building tetgen standalone seems to work, at least as library. @annegehrke, maybe try compiling tetgen by

make tetgen

instead of

make tetlib

as well.

[bsumirak]

I'm still betting it's an fPIC issue. The tetgen lib (of the ug4 tool) is statically built without -fPIC added to the compiler flags. When you add the line set_property(TARGET tet PROPERTY POSITION_INDEPENDENT_CODE ON) after the add_library command in tools/tetgen/CMakeLists.txt and recompile, does that resolve the issue?

[annegehrke]

Thank you very much for your contributions!

I tested the advise of @bsumirak but it made no difference (CXXFLAGS = -03 -fPIC was still set). I got the same error message.

It was possible to build the tetgen standalone by typing make tetgen.

@stephanmg Your guess was right: echo _Z6dstored | c++filt yielded dstore(double). What does that mean?

[mastep84]

FIY:

CXXFLAGS = -03 -fPIC instead of line 22 in the tetgen makefile:

https://github.com/UG4/tool_tetgen/blob/0d664a9831da2292ab48ba44880edd3ebbb211f0/makefile#L22

This has previously resolved the same kind of issue in case of a Ubuntu on Windows Subsystem for Linux build.

[stephanmg]

@annegehrke yeah I checked this already, not really helpful. I think @bsumirak hinting to was a good idea, try if this or @mastep84 version helps.

Btw.: Could you state your OS and toolchain?

[bsumirak]

Pondering this once more, I first want to clarify what your setup is. This is what I gather, correct me if I am wrong:

1. You used uginstall to download the tetgen sources to $UG4_ROOT/tools/tetgen.
2. But you do not build it alongside ug4 (with -Dtetgen=ON).
3. instead you build it separately, using the Makefile included in the tetgen source.
4. Then you specify -DTETGEN=$UG4_ROOT/tools/tetgen/ during the ug4 cmake setup.

If that is the case, then modifications to the tetgen CMakeFile would not make any difference. But I think I know what is happening nonetheless. Please try the following:

1. remove $UG4_ROOT/tools/tetgen/predicates.o
2. add the -fPIC to CXXFLAGS and PREDCXXFLAGS in the makefile
3. recompile tetlib (make tetlib)
4. recompile ug4

Working now?

[annegehrke]

@bsumirak Thank you very much for the solution of the problem! You guessed right about my setup and you suggested the right approach :) I could compile ug4 now with tetgen and already tested it by creating a geometry.

Many thanks also to @stephanmg and @mastep84 for your help :)