https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65176
Bug ID: 65176 Summary: config.guess failed to guess machine with 64-bit kernel and 32-bit user space: Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap Assignee: unassigned at gcc dot gnu.org Reporter: hjl.tools at gmail dot com Depending on "uname -m" doesn't work with 64-bit kernel and 32-bit user space: bash-4.3# uname -m x86_64 bash-4.3# gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i686-redhat-linux/4.9.2/lto-wrapper Target: i686-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --enable-plugin --enable-initfini-array --disable-libgcj --with-isl=/builddir/build/BUILD/gcc-4.9.2-20150212/obj-i686-redhat-linux/isl-install --with-cloog=/builddir/build/BUILD/gcc-4.9.2-20150212/obj-i686-redhat-linux/cloog-install --enable-gnu-indirect-function --with-tune=generic --with-arch=i686 --build=i686-redhat-linux Thread model: posix gcc version 4.9.2 20150212 (Red Hat 4.9.2-6) (GCC) bash-4.3# ./config.guess x86_64-unknown-linux-gnu bash-4.3# I am expecting i686-unknown-linux-gnu, not x86_64-unknown-linux-gnu.