arm-linux-gnueabihf/libbfd-2.28-system.so is not an ELF file - it has the wrong magic bytes at the start.

[Darren Conway]

I am running Stretch
I tried to compile a C program mjpg-streamer.
I ran apt-get update and upgrade before doing:

The compiler failed with the following output.

:/tmp/mjpg-streamer/mjpg-streamer-experimental $ cmake ./
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- broken
CMake Error at /usr/share/cmake-3.7/Modules/CMakeTestCCompiler.cmake:51 (message):
  The C compiler "/usr/bin/cc" is not able to compile a simple test program.

  It fails with the following output:

   Change Dir: /tmp/mjpg-streamer/mjpg-streamer-experimental/CMakeFiles/CMakeTmp

I traced the problem to a problem with a lib file:

I copied the file:

-rw-r--r-- 1 root root 748168 Apr 18 09:39 libbfd-2.28-system.so

from a Pi that compiles OK and placed it in the directory:

cd /usr/lib/arm-linux-gnueabihf/

This replaced the file:

-rw-r--r-- 1 root root 748168 May 10 2017 libbfd-2.28-system.so

Note the different dates but same version and same size.
I was then able to compile normally.

When I did the upgrade, I got the message:
ldconfig: /usr/lib/arm-linux-gnueabihf/libbabeltrace.so.1 is not an ELF file - it has the wrong magic bytes at the start.
The file does not seem to have affected anything I am trying to do.

I had the same problem on two different Pi's. Neither had been used to compile programs. As far as I am aware, I haven't done anything that might have caused this problem.