Hi, following up on my own message, I finally had the presence of mind to look at what gdb on armv7 would tell me, if anything, because that build failed as well.
And... it tells quite a bit more than the other two: armv7: {2} gdb /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/build/bootstrap/debug/bootstrap work/rustc-1.73.0-src/bootstrap.core GNU gdb (GDB) 8.3 Copyright (C) 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "armv7--netbsdelf-eabihf". Type "show configuration" for configuration details. For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>. For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/build/bootstrap/debug/bootstrap... [New process 1] Core was generated by `bootstrap'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x60d0fe74 in _cpuset_isset () from /usr/lib/libc.so.12 warning: Unsupported auto-load script at offset 0 in section .debug_gdb_scripts of file /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/build/bootstrap/debug/bootstrap. Use `info auto-load python-scripts [REGEXP]' to list them. (gdb) where #0 0x60d0fe74 in _cpuset_isset () from /usr/lib/libc.so.12 #1 0x03d2bf8c in std::sys::unix::thread::available_parallelism () #2 0x03cff460 in std::thread::available_parallelism () #3 0x0383ed74 in <bootstrap::flags::Flags as clap_builder::derive::Args>::augment_args::DEFAULT_VALUE::{{closure}} () at flags.rs:110 #4 0x0347d7a8 in core::ops::function::FnOnce::call_once () at /usr/pkgsrc/wip/rust/work/rustc-1.72.0-src/library/core/src/ops/function.rs:250 #5 0x0347f29c in core::ops::function::FnOnce::call_once () at /usr/pkgsrc/wip/rust/work/rustc-1.72.0-src/library/core/src/ops/function.rs:250 #6 0x033f87c8 in once_cell::sync::Lazy<T,F>::force::{{closure}} () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/lib.rs:1212 #7 0x033f8be0 in once_cell::sync::OnceCell<T>::get_or_init::{{closure}} () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/lib.rs:1023 #8 0x0383c624 in once_cell::imp::OnceCell<T>::initialize::{{closure}} () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/imp_std.rs:85 #9 0x03cdf5d8 in core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut () #10 0x03ce0d98 in once_cell::imp::initialize_or_wait () #11 0x0383c010 in once_cell::imp::OnceCell<T>::initialize () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/imp_std.rs:81 #12 0x033f9880 in once_cell::sync::OnceCell<T>::get_or_try_init () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/lib.rs:1063 #13 0x033f89b0 in once_cell::sync::OnceCell<T>::get_or_init () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/lib.rs:1023 #14 0x033f86a8 in once_cell::sync::Lazy<T,F>::force () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/lib.rs:1211 #15 0x033f8580 in <once_cell::sync::Lazy<T,F> as core::ops::deref::Deref>::deref () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/once_cell-1.12.0/src/lib.rs:1221 #16 0x03414ff4 in <bootstrap::flags::Flags as clap_builder::derive::Args>::augment_args () at flags.rs:110 #17 0x0340eee0 in <bootstrap::flags::Flags as clap_builder::derive::CommandFactory>::command () at flags.rs:33 #18 0x0383d784 in clap_builder::derive::Parser::parse_from () at /usr/pkgsrc/wip/rust/work/rustc-1.73.0-src/vendor/clap_builder-4.2.4/src/derive.rs:52 #19 0x0340e7a4 in bootstrap::flags::Flags::parse () at flags.rs:199 #20 0x033d73c8 in bootstrap::config::Config::parse_inner () at config.rs:1117 #21 0x03681018 in bootstrap::config::Config::parse () at config.rs:1113 #22 0x03381578 in bootstrap::main () at bin/main.rs:20 (gdb) i reg r0 0x0 0 r1 0x0 0 r2 0x0 0 r3 0x1 1 r4 0x0 0 r5 0x60ed41e8 1626161640 r6 0x1 1 r7 0x0 0 r8 0x0 0 r9 0x7ff64328 2146845480 r10 0x3d61425 64361509 r11 0x7ff642cc 2146845388 r12 0x7ff642d0 2146845392 sp 0x7ff642c0 0x7ff642c0 lr 0x3d2bf8c 64143244 pc 0x60d0fe74 0x60d0fe74 <_cpuset_isset+36> cpsr 0x20030010 537067536 (gdb) x/i 0x60d0fe74 => 0x60d0fe74 <_cpuset_isset+36>: ldr r3, [r1, r2, lsl #2] (gdb) At least it gives a bit of clue about where to go looking for the null pointer de-reference, so that's at least something... Meanwhile, the arm64/9.0 build succeeded, and the sparc64/10.0_BETA build appears to have passed this particular hurdle. Regards, - Havard