After the switch to lld, even a minimal Fuchsia binary page-faults at runtime. The backtraces point to the `FnOnce::call_once` vtable shim added in https://github.com/rust-lang/rust/pull/54183. I'm not making use of `Box<dyn FnOnce>` anywhere in Fuchsia directly, but it's possible an std use has snuck in (edit: but it definitely shouldn't be the first function run by the loader?). cc @petrhosek ``` [00028.682] 09877.09884> PageFault: 473109 free pages [00028.682] 09877.09884> PageFault: MemoryUsed: proc 1129 10M 'fshost' [00028.683] 09877.09884> PageFault: MemoryUsed: proc 2945 72M 'blobfs:/blob' [00028.683] 09877.09884> PageFault: MemoryUsed: proc 3378 8M 'minfs:/data' [00028.684] 01045.01271> devmgr: crash_analyzer_listener: analyzing exception type 0x108 [00028.684] 01105.01119> <== fatal exception: process ./connectivity_testing_lib_test[9877] thread initial-thread[9884] [00028.684] 01105.01119> <== fatal page fault, PC at 0x1728953ca000 [00028.684] 01105.01119> CS: 0 RIP: 0x1728953ca000 EFL: 0x10202 CR2: 0x4c74dfa5 [00028.684] 01105.01119> RAX: 0 RBX: 0 RCX: 0 RDX: 0 [00028.684] 01105.01119> RSI: 0x79f30ec5a000 RDI: 0x4c74dfa5 RBP: 0 RSP: 0x1e00e749ff8 [00028.684] 01105.01119> R8: 0 R9: 0 R10: 0 R11: 0 [00028.684] 01105.01119> R12: 0 R13: 0 R14: 0 R15: 0 [00028.684] 01105.01119> errc: 0x4 [00028.684] 01105.01119> bottom of user stack: [00028.684] 01105.01119> 0x000001e00e749ff8: 00000000 00000000 |................| [00028.684] 01105.01119> arch: x86_64 [00028.684] 01105.01119> read_mem @0x8 FAILED 8 [00028.684] 01105.01119> {{{reset}}} [00028.684] 01105.01119> {{{module:0x1e8931d8:<VMO#9844=connectivity_testing_:elf:30922f7ca740fd8a}}} [00028.684] 01105.01119> {{{mmap:0x1728953a8000:0x22000:load:0x1e8931d8:r:0}}} [00028.684] 01105.01119> {{{mmap:0x1728953ca000:0x1000:load:0x1e8931d8:rx:0x22000}}} [00028.684] 01105.01119> {{{mmap:0x1728953cb000:0x2000:load:0x1e8931d8:rw:0x23000}}} [00028.684] 01105.01119> {{{module:0x1e8931d9:<VMO#1033=vdso/full>:elf:329e77f0c225f0f29e7d914d7bf2c55f89f90f43}}} [00028.684] 01105.01119> {{{mmap:0x79f30ec[28.682] 09877.09884> 5a000:0x6000:load:0x1e8931d9:r:0}}} [00028.684] 01105.01119> {{{mmap:0x79f30ec60000:0x1000:load:0x1e8931d9:rx:0x6000}}} [00028.684] 01105.01119> bt#01: pc 0x1728953ca000 sp 0x1e00e749fPageFault: 473109 free pagesf8 [00028.684] 01105.01119> bt#02: end [00028.684] 01105.01119> {{{bt:1:0x1728953ca000}}} [28.682] 09877.09884> PageFault: MemoryUsed: proc 1129 10M 'fshost' [28.683] 09877.09884> PageFault: MemoryUsed: proc 2945 72M 'blobfs:/blob' [28.683] 09877.09884> PageFault: MemoryUsed: proc 3378 8M 'minfs:/data' [28.684] 01045.01271> devmgr: crash_analyzer_listener: analyzing exception type 0x108 [28.684] 01105.01119> <== fatal exception: process ./connectivity_testing_lib_test[9877] thread initial-thread[9884] [28.684] 01105.01119> <== fatal page fault, PC at 0x1728953ca000 [28.684] 01105.01119> CS: 0 RIP: 0x1728953ca000 EFL: 0x10202 CR2: 0x4c74dfa5 [28.684] 01105.01119> RAX: 0 RBX: 0 RCX: 0 RDX: 0 [28.684] 01105.01119> RSI: 0x79f30ec5a000 RDI: 0x4c74dfa5 RBP: 0 RSP: 0x1e00e749ff8 [28.684] 01105.01119> R8: 0 R9: 0 R10: 0 R11: 0 [28.684] 01105.01119> R12: 0 R13: 0 R14: 0 R15: 0 [28.684] 01105.01119> errc: 0x4 [28.684] 01105.01119> bottom of user stack: [28.684] 01105.01119> 0x000001e00e749ff8: 00000000 00000000 |................| [28.684] 01105.01119> arch: x86_64 [28.684] 01105.01119> read_mem @0x8 FAILED 8 [28.684] 01105.01119> bt#01: pc 0x1728953ca000 sp 0x1e00e749ff8 [28.684] 01105.01119> bt#02: end [28.684] 01105.01119> #1 0x00001728953ca000 in core::ops::function::FnOnce::call_once::_$u7b$$u7b$vtable.shim$u7d$$u7d$::h10568ef9220c4b73 /b/s/w/ir/kitchen-workdir/rust/src/libcore/ops/function.rs:238 <<VMO#9844=connectivity_testing_>+0x22000 ```