mspdebug sim mode incompatible with msp430-gdb?

[jmfriedt]

I thought I had seen some report about this issue but cannot identify a formal description. I have just compiled on Debian GNU/Linux unstable the content of the archive found at https://www.ti.com/tool/MSP430-GCC-OPENSOURCE (Mitto Systems GCC source files). All compiles fine until gdb with Python-2.7 support which was just removed from the build script, and I additionally added make CFLAGS=-DDEBUG_GDB at the end of the build script.
I compiled a basic C program with the resulting

.../install/usr/local/bin/msp430-elf-gcc -o exec.msp430 -mmcu=msp430f149 src.c -L .../msp430-gcc-support-files/include

(not really happy with defining a linker script located in a directory named include but this is the way they organized the files). The executable sounds good with

exec.msp430: ELF 32-bit LSB executable, TI msp430, version 1 (embedded), statically linked, with debug_info, not stripped

but then compiling this mspdebug and trying the simulator mode with
.../mspdebug/mspdebug sim "prog exec.msp430" gdb I end up with

Chip info database from MSP430.dll v3.15.0.1 Copyright (C) 2013 TI, Inc.
Simulation started, 0x20000 bytes of RAM
Chip ID data:
  ver_id:         ffff
  ver_sub_id:     0000
  revision:       ff
  fab:            ff
  self:           ffff
  config:         7f
  fuses:          00
warning: unknown chip

and of course msp430-gdb is somewhat unhappy

Reading symbols from exec.msp430...
I'm sorry, Dave, I can't do that.  Symbol format `elf32-msp430' unknown.

so I am not sure how these two issues might be related and at the end fail in debugging in simulator mode.
Any insight would be welcome, thanks.