Description:

checking for sysmp... no
checking for getsysinfo... no
checking for table... no
checking for sysctl... yes
checking for unistd.h... (cached) no
checking for getpagesize... (cached) yes
checking for working mmap... no
checking for working strncmp... no
updating cache ../config.cache
creating ./config.status
creating Makefile
creating testsuite/Makefile
creating config.h
Configuring gcc...
loading cache ../config.cache
checking LIBRARY_PATH variable... ok
checking GCC_EXEC_PREFIX variable... ok
checking host system type... x86_64-unknown-linux-gnu
checking target system type... x86_64-unknown-linux-gnu
checking build system type... x86_64-unknown-linux-gnu
checking for gcc... (cached) gcc
checking whether the C compiler (gcc -march=x86-64 -O2 -pipe -Wl,-O1,--sort-common,--as-needed,-z,relro) works... yes
checking whether the C compiler (gcc -march=x86-64 -O2 -pipe -Wl,-O1,--sort-common,--as-needed,-z,relro) is a cross-compiler... no
checking whether we are using GNU C... (cached) yes
checking whether gcc accepts -g... (cached) yes
checking whether gcc and cc understand -c and -o together... (cached) yes
checking for gnatbind... no
checking for compiler driver that understands Ada... no
checking whether gcc accepts -Wno-long-long... yes
checking how to run the C preprocessor... (cached) /lib/cpp
checking for inline... (cached) inline
checking for volatile... yes
checking for long double... yes
checking for long long int... yes
checking for __int64... no
checking for built-in _Bool... yes
checking size of short... 2
checking size of int... 4
checking size of long... 8
checking size of long long... 8
checking execution character set... unknown
configure: error: *** Cannot determine host character set.
Configure in /build/libstdc++5/src/gcc-build/gcc failed, exiting.
==> ERROR: A failure occurred in build().
Aborting...

Steps to reproduce:
sudo extra-x86_64-build