[Bug libstdc++/70569] New: configure: error: source directory already configured; run "make distclean" there first

["mario.silva.costa at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70569

            Bug ID: 70569
           Summary: configure: error: source directory already configured;
                    run "make distclean" there first
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mario.silva.costa at gmail dot com
  Target Milestone: ---

Created attachment 38208
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38208&action=edit
libstdc++-v3 config.log

on ubuntu 14.04 64 bit.

./configure --disable-multilib && make

fails to compile.

mkdir -p -- x86_64-pc-linux-gnu/libstdc++-v3
Checking multilib configuration for libstdc++-v3...
Configuring stage 1 in x86_64-pc-linux-gnu/libstdc++-v3
configure: creating cache ./config.cache
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
configure: error: source directory already configured; run "make distclean"
there first
make[2]: *** [configure-stage1-target-libstdc++-v3] Error 1
make[2]: Leaving directory `/home/atritoman/gcc'
make[1]: *** [stage1-bubble] Error 2
make[1]: Leaving directory `/home/atritoman/gcc'
make: *** [all] Error 2