Hello everyone, After 2 hours of trying to make the configure script find three libraries, I decided to ask someone before I throw my computer through the window. This is the picture: my code uses three libraries, and these are installed in non-standard directories (under $HOME/Lib). I'm using CGAL, loki, superlu and blas. So, I configure my code with the following command: ./configure CXX=g++-mp-4.3 CXXFLAGS="-I$HOME/Lib/loki/include -I$HOME/Lib/CGAL/include -I$HOME/Lib/SuperLU" LDFLAGS="-L$HOME/Lib/loki/lib -L$HOME/Lib/CGAL/lib -L$HOME/Lib/SuperLU" LIBS="-lblas -lsuperlu_3.0 -lCGAL -lloki" So you see I'm using a different version for the C++ compiler than that of the system. I also include the include paths and paths were all the libraries are. So when I try to compile the code I get: Undefined symbols: "_dtrsv__", referenced from: _sp_dtrsv in libsuperlu_3.0.a(dsp_blas2.o) _sp_dtrsv in libsuperlu_3.0.a(dsp_blas2.o) ld: symbol(s) not found collect2: ld returned 1 exit status Those symbols belong to the blas library. So it turns out that superlu depends on the blas library. I compiled superlu with its own blas library so the libblas.a is also in the same directory where libsuperlu_3.0.a is. So I don't understand what's going on. I found that the blas library is also installed in the system in /usr/lib: >$ ls /usr/lib/*blas*/usr/lib/libblas.dylib /usr/lib/libcblas.dylib so probably it's trying to find the symbols in the wrong library? Now, when I hard-code the blas library in the Makefile.am, my code compiles fine: noinst_PROGRAMS = fem.out fem_out_SOURCES = $(cxx_sources) main.cxx fem_out_LDADD = libxfem.a /Users/aaragon/Lib/SuperLU/libblas.a But of course this is a bad hack. Then, I tried for a long time to make the macros detect the libraries, but not a single success! AC_SEARCH_LIBS([dgemm], [blas cblas],,[echo "ERROR: Could not blas library" && exit 1]) # I think the macro above detects the one installed in the system AC_SEARCH_LIBS([dCreate_CompCol_Matrix], [superlu_3.0 superlu],,[echo "ERROR: Could not find superlu" && exit 1]) # I cannot get anything from the call above AC_CHECK_LIB([superlu_3.0],[_dCreate_CompCol_Matrix],,"echo ERROR: superlu not found." && exit 1) #another attempt, failure Why are the macros not detecting the libraries? I specify in the command line the paths were the libraries are, so I guess they should be taken into account when these macros search, right? Am I missing something??? Please help!!! Thank you, aa -- View this message in context: http://www.nabble.com/library-checks-are-driving-me-crazy%21-tp16245235p16245235.html Sent from the Gnu - Autoconf - General mailing list archive at Nabble.com. _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf