GDB not always able to show source.

Hello,

  I've been having a really strange issue lately. I'm cross compiling
binaries targeting MIPS I, and sometimes, gdb can't display
source information. The same binary will work with some versions of gdb,
and not with others. I'm just confused at this point, and if anyone can
enlighten me, I'd be really grateful.

  Here's a small rundown. I'll use this binary here:
https://static.grumpycoder.net/pixel/test-gdb.elf

  First things first, the binary can be properly disassembled and show all
of its source information using objdump:

mipsel-linux-gnu-objdump --disassemble -S -l test-gdb.elf

The output of the command above will display properly all of the file and
line number information. Now, on my Ubuntu 24.04.1 LTS machine, using its
gdb binary, I can also display line information properly:

pixel@Jowy:~/Downloads$ gdb ./test-gdb.elf
GNU gdb (Ubuntu 15.0.50.20240403-0ubuntu1) 15.0.50.20240403-git
Reading symbols from ./test-gdb.elf...
(gdb) info line *0x800334b0
Line 44 of "src/application.cpp" starts at address 0x800334b0
<_ZN5psyqo11Application3runEv>
   and ends at 0x800334bc <_ZN5psyqo11Application3runEv+12>.

But when using its gdb-multiarch binary, I can't:
pixel@Jowy:~/Downloads$ gdb-multiarch ./test-gdb.elf
GNU gdb (Ubuntu 15.0.50.20240403-0ubuntu1) 15.0.50.20240403-git
Reading symbols from ./test-gdb.elf...
(gdb) info line *0x800334b0
No line number information available for address 0x800334b0
<_ZN5psyqo11Application3runEv>

Now, to eliminate a potential problem with the Ubuntu packages, I built gdb
16.2 myself, using the following flags, and I also am unable to see the
line information for this address:

configure --disable-gdbtk --disable-shared --disable-readline
--with-system-readline --with-expat --with-system-zlib --without-guile
--without-babeltrace --enable-tui --with-lzma --without-python
--with-xxhash --enable-64-bit-bfd --enable-targets=all --disable-sim

pixel@Jowy:~/sources/gdb-16.2/build/gdb$ ./gdb ~/Downloads/test-gdb.elf
GNU gdb (GDB) 16.2
Reading symbols from /home/pixel/Downloads/test-gdb.elf...
(gdb) info line *0x800334b0
No line number information available for address 0x800334b0
<_ZN5psyqo11Application3runEv>

At this point, I'm confused as to why some versions of gdb (which aren't
built in "multiarch" mode) will properly display the line information, and
why some others (which are built in "multiarch" mode) will not.

Anyone has any clue about what am I missing? Did I stumble upon a gdb bug?

Thanks,

  -- Nicolas Noble