Building examples on Ubuntu with Qt-5.13.0

[jsulm]

@gibbogle Did you install build-essential Ubuntu package as well?
As the error message states it can't find C++ compiler.
See https://doc.qt.io/qt-5/linux.html

sudo apt-get install build-essential libgl1-mesa-dev

[gibbogle]

@jsulm said in Building examples on Ubuntu with Qt-5.13.0:

sudo apt-get install build-essential libgl1-mesa-dev

Both are already the newest version.

[gibbogle]

@jsulm
The kit has the compiler as: GCC (C++, x86 64bit in /usr/bin), and in /usr/bin I see gcc as a link to gcc-5.
'gcc -v' shows

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 5.4.0-6ubuntu1~16.04.11' --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 5.4.0-6ubuntu1~16.04.11)

[jsulm]

@gibbogle Please check your Kit: are there any warnings/errors?
Is C++ compiler set as g++?

[gibbogle]

@jsulm
I don't see any warnings or errors associated with Qt-5.13.0.
How do I set gcc to g++?

[gibbogle]

@jsulm
To better express this: in the list of Compilers I see just many versions of GCC and some of Clang.

[jsulm]

@gibbogle Can you show a screenshot of your Kit configuration?

[gibbogle]

@jsulm Before I try to find out how to that, perhaps there is a simple solution.
In Compilers, the Auto-detected list has two entries for GCC (C++, x86 64bit in /usr/bin) and two for GCC 5(C++, x86 64bit in /usr/bin). When I select these I see that the associated compiler paths are all to a version of g++:
/usr/bin/g++
/usr/bin/x86_64-linux-gnu-g++
/usr/bin/g++-5
/usr/bin/x86_64-linux-gnu-g++-5

I know that the kit is using GCC, not GCC 5, but there is no way to see which of the first two in the above list it corresponds to (g++ or x86_64-linux-gnu-g++).

Now I see that they all point to g++-5

gib@gigabyte:/usr/bin$ ls -al g++
lrwxrwxrwx 1 root root 5 May 20 2017 g++ -> g++-5
-rwxr-xr-x 1 root root 919832 Aug 28 2018 g++-5
lrwxrwxrwx 1 root root 5 May 20 2017 x86_64-linux-gnu-g++ -> g++-5
lrwxrwxrwx 1 root root 5 Aug 28 2018 x86_64-linux-gnu-g++-5 -> g++-5

[gibbogle]

@jsulm I don't know how to get a screenshot in Linux.
The kit for Qt-5.13.0 is (default) has:
Compiler: GCC (C++, x86 64bit in /usr/bin)
Environment: No changes to apply.
Qt version: Qt 5.13.0 (gcc_64)

[gibbogle]

@gibbogle
In fact (* got stripped in the copy-and-paste) I typed:
ls -al * g++ *
(without the spaces)

[gibbogle]

This post is deleted!

[gibbogle]

This post is deleted!

[gibbogle]

@jsulm I just reminded myself that the build does find and use g++, and makes the executable. I located it, and it runs OK. So the configure errors about g++ are perhaps not important, but there is still the problem with the missing directory tree.

Should I make a bug report?

[jsulm]

@gibbogle said in Building examples on Ubuntu with Qt-5.13.0:

missing directory tree

You mean in QtCreator? This is not a bug - if qmake fails the project structure will not be updated.
What happens if you call qmake in a terminal instead in QtCreator?

[gibbogle]

@jsulm But qmake doesn't fail when I do Build > Run qmake, and the build does succeed.
I've now found that if I build for the first time then close the project (no project tree), then reopen the project, I do get a project tree. You might not call this a bug, but it's definitely confusing and undesirable.

There is also the issue that after a successful build, clicking the green arrow to run the program gives the "Could not find the executable" popup. (I just discovered that on reopening the project - and seeing a project tree - the green arrow does execute the program.) It seems likely that all these issues stem from the same cause.

Yes, this is all within Qt Creator.