build-obj ELF output format - attempt to use null value #11451

% zig version
0.10.0-dev.1855+a315d51c0

# build-obj without -ofmt=elf works properly
% zig build-obj empty.zig
% file empty.o
empty.o: Mach-O 64-bit object x86_64

% zig build-obj empty.zig -ofmt=elf
thread 635830 panic: attempt to use null value
/Users/mike/scratch/zig/src/link/Elf.zig:2802:69: 0x10abf26df in link.Elf.writeAllGlobalSymbols (zig1)
    const syms_sect = &self.sections.items[self.symtab_section_index.?];
                                                                    ^
/Users/mike/scratch/zig/src/link/Elf.zig:1009:35: 0x10abc1374 in link.Elf.flushModule (zig1)
    try self.writeAllGlobalSymbols();
                                  ^
/Users/mike/scratch/zig/src/link/Elf.zig:946:46: 0x10abad09c in link.Elf.flush (zig1)
        .Exe, .Obj => return self.flushModule(comp),
                                             ^
/Users/mike/scratch/zig/src/link.zig:601:68: 0x10abaa222 in link.File.flush (zig1)
            .elf => return @fieldParentPtr(Elf, "base", base).flush(comp),
                                                                   ^
/Users/mike/scratch/zig/src/Compilation.zig:2192:28: 0x10ab79b40 in Compilation.flush (zig1)
    try comp.bin_file.flush(comp); // This is needed before reading the error flags.
                           ^
/Users/mike/scratch/zig/src/Compilation.zig:2174:23: 0x10ab6f9eb in Compilation.update (zig1)
        try comp.flush();
                      ^
/Users/mike/scratch/zig/src/main.zig:3101:20: 0x10ab043f0 in main.updateModule (zig1)
    try comp.update();
                   ^
/Users/mike/scratch/zig/src/main.zig:2788:17: 0x10aa1cecd in main.buildOutputType (zig1)
    updateModule(gpa, comp, hook) catch |err| switch (err) {
                ^
/Users/mike/scratch/zig/src/main.zig:214:31: 0x10a9e40c7 in main.mainArgs (zig1)
        return buildOutputType(gpa, arena, args, .{ .build = .Obj });
                              ^
/Users/mike/scratch/zig/src/stage1.zig:48:24: 0x10a9e392a in main (zig1)
        stage2.mainArgs(gpa, arena, args) catch unreachable;
                       ^
???:?:?: 0x120d3451d in ??? (???)
???:?:?: 0x0 in ??? (???)
[1]    77062 abort      zig build-obj empty.zig -ofmt=elf