Panic at start.zig when linking a C library: cast causes pointer to be null

[TUSF]

Zig Version

0.12.0-dev.694+937e8cb70

Steps to Reproduce and Observed Behavior

Not entirely certain.

I have two repos, both Zig packages for C libraries. I've also ported over the code needed to run the original library's tests, and those work fine. However, I started working on some wrappers for a Zig API on them, and now things are weird when I try to run the tests.

More specifically, I was trying to get some basic tests going on my libcss package, and while the normal C tests (seem to) work fine, when I try to use the Zig tests (which don't actually have any tests yet) I get the following error:

$ zig build test
run test: error: thread 18381 panic: cast causes pointer to be null
/home/jere/zig/0.12.0-dev.694+937e8cb70/files/lib/std/start.zig:478:41: 0x23e8ed in main (test)
        const phdrs = (@as([*]elf.Phdr, @ptrFromInt(at_phdr)))[0..at_phnum];
                                        ^
???:?:?: 0x7f22fe9a9d8f in ??? (libc.so.6)
Unwind information for `libc.so.6:0x7f22fe9a9d8f` was not available, trace may be incomplete


run test: error: the following command terminated with signal 6 (expected exited with code 0):
/mnt/j/code/projects/netsurf/libcss/zig-cache/o/5643e278783a8ad5a66a6a284332a371/test --listen=-
Build Summary: 171/173 steps succeeded; 1 failed (disable with --summary none)
test transitive failure
└─ run test failure

This seems to only be a problem when linking libc, and running the tests on Linux. (the tests run fine on Windows) However, I don't really know what the condition for this error is, because I have another package libwapcaplet (which libcss depends on) where this doesn't happen: the Zig test (which actually has one test) runs fine.

Expected Behavior

To start up properly without panicing.

[kcbanner]

This sounds like #16281.

I made a fix here for a similar issue #16977, but noted at the bottom it doesn't fix all cases.