After a brand new install on ubuntu 16.04, octave 4.2.1 resides in /opt/octave-4.2.1. Octave appears to work fine, but installing any package fails as in:
address@hidden:~$ octave --no-gui
GNU Octave, version 4.2.1
Copyright (C) 2017 John W. Eaton and others.
This is free software; see the source code for copying conditions.
There is ABSOLUTELY NO WARRANTY; not even for MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. For details, type 'warranty'.
Octave was configured for "x86_64-pc-linux-gnu".
Additional information about Octave is available at
http://www.octave.org.
Please contribute if you find this software useful.
For more information, visit
http://www.octave.org/get-involved.htmlRead
http://www.octave.org/bugs.html to learn how to submit bug reports.
For information about changes from previous versions, type 'news'.
octave:1> pkg install -forge struct
configure: error: in `/tmp/oct-EbV2X7/struct-1.0.14/src':
configure: error: C++ compiler cannot create executables
See `config.log' for more details
checking for mkoctfile... /opt/octave-4.2.1/bin/mkoctfile-4.2.1
checking for octave-config... /opt/octave-4.2.1/bin/octave-config-4.2.1
checking for a sed that does not truncate output... /bin/sed
checking whether the C++ compiler works... no
pkg: error running the configure script for struct.
error: called from
configure_make at line 78 column 9
install at line 192 column 7
pkg at line 394 column 9
octave:1> quit
address@hidden:~$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.0-6ubuntu1~16.04.4' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.4)