c++11 std::unique_ptr error cmake 3.11.3 bootstrap : <p>I am trying to bootstrap cmake 3.11.3 on Ubuntu 16.04.4 LTS xenial.</p>

<p>I have upgrade my gnu g++ compiler as follows:</p>

<pre><code>&gt; $ g++ --version
g++ (Ubuntu 8.1.0-5ubuntu1~16.04) 8.1.0 Copyright (C) 2018 Free
Software Foundation, Inc. This is free software; see the source for 
copying conditions.  There is NO warranty; not even for MERCHANTABILITY 
or FITNESS FOR A PARTICULAR PURPOSE.
</code></pre>

<p>And manually re-pointed the symbolic links:</p>

<pre><code>$ ll /usr/bin/*g++*
lrwxrwxrwx 1 root root       5 Jun  8 16:57 /usr/bin/g++ -&gt; g++-8*
-rwxr-xr-x 1 root root  919832 Apr 24 15:02 /usr/bin/g++-5*
lrwxrwxrwx 1 root root      22 Jun  6 04:26 /usr/bin/g++-8 -&gt; x86_64-linux-gnu-g++-8*
lrwxrwxrwx 1 root root      22 Jun  8 16:58 /usr/bin/x86_64-linux-gnu-g++ -&gt; x86_64-linux-gnu-g++-8*
lrwxrwxrwx 1 root root       5 Apr 24 15:02 /usr/bin/x86_64-linux-gnu-g++-5 -&gt; g++-5*
-rwxr-xr-x 1 root root 1071984 Jun  6 04:26 /usr/bin/x86_64-linux-gnu-g++-8*
</code></pre>

<p>However, I get the following error in the configuration of cmake:</p>

<pre><code>$ sudo ./bootstrap 
---------------------------------------------
CMake 3.11.3, Copyright 2000-2018 Kitware, Inc. and Contributors
Found GNU toolchain
C compiler on this system is: gcc       
C++ compiler on this system is: g++          
Makefile processor on this system is: make
g++ has setenv
g++ has unsetenv
g++ does not have environ in stdlib.h
g++ has stl wstring
g++ has &lt;ext/stdio_filebuf.h&gt;
---------------------------------------------
make: Warning: File 'Makefile' has modification time 2.3 s in the future
make: 'cmake' is up to date.
make: warning:  Clock skew detected.  Your build may be incomplete.
loading initial cache file /mnt/ganymede/user/gpeytavi/srv_admin/software/cmake-3.11.3/Bootstrap.cmk/InitialCacheFlags.cmake
CMake Error at CMakeLists.txt:92 (message):
  The C++ compiler does not support C++11 (e.g.  std::unique_ptr).


-- Configuring incomplete, errors occurred!
See also "/mnt/ganymede/user/gpeytavi/srv_admin/software/cmake-3.11.3/CMakeFiles/CMakeOutput.log".
See also "/mnt/ganymede/user/gpeytavi/srv_admin/software/cmake-3.11.3/CMakeFiles/CMakeError.log".
---------------------------------------------
Error when bootstrapping CMake:
Problem while running initial CMake
---------------------------------------------
</code></pre>

<p>Any idea why I get a c++11 <code>std::unique_ptr</code> non-compliant error?</p>
