Comment 2 for bug 1747711

It is also an issue on bionic:

 $ schroot -u root -c bionic-amd64
(bionic-amd64)root@impulse:/tmp# echo "int main() { return 0; }" > foo.c
(bionic-amd64)root@impulse:/tmp# gcc -o foo foo.c
(bionic-amd64)root@impulse:/tmp# file foo
foo: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=5222fe7f5f12ee8d286b84f93c981cab98ad382a, not stripped

But not on xenial:

 $ schroot -u root -c xenial-amd64
(xenial-amd64)root@impulse:/tmp# echo "int main() { return 0; }" > foo.c
(xenial-amd64)root@impulse:/tmp# gcc -o foo foo.c
(xenial-amd64)root@impulse:/tmp# file foo
foo: 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, BuildID[sha1]=5a079b5be569b3e0527b9685f1c7811fb193d37c, not stripped

Using gcc from xenial and file from bionic though the file is identified as an executable so I don't think its file.