Unsolved Building examples on Ubuntu with Qt-5.13.0

[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.