Strange gcc 6.2.0 output problem

[Nokturnis]

Hi, I’m new here so please excuse me if I’ve posted in the wrong section.
I have recently updated from Kubuntu 16.04 to Kubuntu 16.10 which comes with gcc 6.2.0.
If I try to launch an application compiled with gcc 6.2.0 from Dolphin (or Krusader) it doesn’t work.

Instead I get the “Choose application” window. By right-clicking on the file, file properties, file type options, it looks like the file is seen as a shared lib (although it isn’t, it’s an executable). If launched from the console, app works as expected.
The problem doesn’t appear if the application is complied with clang.
I’ve added a few screenshots to illustrate the problem.
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[clivejo]

Is the file you are trying to run set as executable ?

[Nokturnis]

Yes, it is.
gcc -o hwc hwc.c does not work.
clang -o hwc hwc.c works.
Executables compiled with older versions of gcc also work.

[jlittle]

What happens if you try and run it in a terminal?

(I'm still on Xenial but have gcc 6.2.0 from the ubuntu-toolchain-r/test ppa, and have no trouble.)

[Nokturnis]

As I said in my original post, launching it from the terminal works as expected.

[Nokturnis]

Strange. If I compress with UPX an executable compiled with gcc 6.2.0, I get a segmentation fault. This does not happen to executables compiled with clang or older versions of gcc.
UPX 3.91

[jlittle]

As I said in my original post, launching it from the terminal works as expected.

Sorry, I missed that.

Dolphin sees my 6.2 binaries as "application/x-executable", but yours are showing as "application/x-sharedlib". This is appropriate for .so files (I presume, because on my system they do.) What does the file command say? I expect it will say

hwc: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=[i]whatever in hex[/i], not stripped

I wonder if you have an alias, environment variable, or rc file influencing gcc. If I add -fPIC -shared to the gcc command, I get an application/sharelib, but the executable crashes instantly. There are also "specs" files, but if you wouldn't have changed something there without understanding it.

[Nokturnis]

file command for exe compiled with gcc:

hwc: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=hex number, not stripped

compiled with clang:

hwc: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, not stripped

I have not touched the "specs" files and the env command doesn't show any strange environment variable.
Could something have happened during the update from 16.04 to 16.10?

[Nokturnis]

Problem still exists. I did a "gcc -dumpspecs" but I don't know where or what to look.
dumpedspecs.txt.zip

[kubicle]

Try building with the "-no-pie" option for gcc.
https://wiki.ubuntu.com/SecurityTeam/PIE

[Nokturnis]

YES!!! Now it works! Thank you!
Any idea how to make this default?