Bad interaction of -fuse-ld=lld and statically linked libc++

[rao94583]

Our platform is Ubuntu 22.04. We import the OpenUSD package as a prebuilt tarball (built with clang) into bazel targets for use within our code-base. A small test program that exercises some basic functionality in OpenUSD crashes during static initialization with an error like this:

a_rao@a-rao-ubuntu:$ bazel test //examples/hello_world:test_usd 
test_usd: mbrtowc.c:104: __mbrtowc: Assertion `__mbsinit (data.__statep)' failed.
Aborted (core dumped)

After much debugging, the culprit appears to be -fuse-ld=lld, which also apparently causes libc++.a, libc++abi.a and libunwind.a to be statically linked. Either of these by themselves is fine, but together, they cause the crash.

Also: using clang++ instead of clang also fixes the problem (without changing anything else).

The workaround is to add linkopts to the build rule for the test program:

cc.test(
    name = "test_usd",
    srcs = ["test_usd.cpp"],
    args = ["/tmp/hello_world.usda"],
    copts = [
        "-Wno-#pragma-messages",
        "-Wno-deprecated-volatile",
    ],
    linkopts = [
        "-fuse-ld=ld",
        "-lc++",
        "-lc++abi",
        "-lunwind",
    ],
    deps = [
        "//external/OpenUSD:usd_tf",
        "//external/OpenUSD:usd_usd",
        "//external/OpenUSD:usd_usdGeom",
    ],
)