gdb 8.2 can't recognized executable file on macOS Mojave 10.14

The problem is that clang-1000.11.45.2 distributed with Apple LLVM version 10.0.0 adds a new load command to o-mach executables named LC_BUILD_VERSION.

$ otool -l test.o
...
Load command 1
       cmd LC_BUILD_VERSION
   cmdsize 24
  platform macos
       sdk n/a
     minos 10.14
    ntools 0
...

From the apple source:

/*
 * The build_version_command contains the min OS version on which this
 * binary was built to run for its platform.  The list of known platforms and
 * tool values following it.
 */

So currently bfd (the program used by gdb to manipulate executables) is not able to interpret this command and returns the error.

As a temporary solution, you can edit the bfd sources code provides with gdb.

First, download gdb-8.0.1 sources from mirrors. Then add to gdb-8.0.1/bfd/mach-o.c the following code at line 4649 :

case BFD_MACH_O_LC_BUILD_VERSION:
break;

Finally inside gdb-8.0.1/include/mach-o/loader.h at line 189:

  BFD_MACH_O_LC_BUILD_VERSION = 0x32

Don't forget to add a , at the end of the line 188 after BFD_MACH_O_LC_VERSION_MIN_WATCHOS = 0x30).

Then process a classic gdb compilation following instructions from the README :

run the ``configure'' script here, e.g.:

    ./configure 
    make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
    make install

Don't forget to sign gdb as explain here. If you still get the (os/kern) failure (0x5) error, just run sudo gdb.

This is a temporary solution in order to wait for a fix from GNU team.

EDIT

Binutils-gdb has been updated, these changes are now implemented in commit fc7b364.

Hope It will be helpful.

I published a temporary brew formula that seems to work, while awaiting for official brew formula to be updated:

brew install https://raw.githubusercontent.com/timotheecour/homebrew-timutil/master/gdb_tim.rb