I used solstutio12.2 to compile a 32-bit R-2.12.0 CC="cc -xc99" CPPFLAGS="-I/opt/csw/include" CFLAGS="-O -xlibmieee" F77=f95 FFLAGS=-O4 CXX="CC -library=stlport4" CXXFLAGS=-O FC=f95 FCFLAGS=$FFLAGS LDFLAGS="-L/opt/csw/lib" export CC CPPFLAGS CFLAGS F77 FFLAGS CXX CXXFLAGS FC FCFLAGS LDFLAGS ./configure --prefix=/apps/R-2.12.0 --with-tcl-config=/opt/csw/lib/tclConfig.sh --with-tk-config=/opt/csw/lib/tkConfig.sh --disable-nls --with-recommended-packages=no Make Make install R .... Platform: sparc-sun-solaris2.10 (32-bit) ....> install.packages("Matrix").... Loading required package: Matrix *** caught segfault *** address 3000000, cause 'memory not mapped' Segmentation Fault - core dumped The downloaded packages are in '/tmp/Rtmp10h8f8/downloaded_packages' Updating HTML index of packages in '.Library' Warning message: In install.packages("Matrix") : installation of package 'Matrix' had non-zero exit status I then removed all the optimization options and compiled again, got same results. The require(Matrix) will cause 'memory not mapped' error each time with a different address. Please help. Jun