I tried to build lang/rust on native aarch64 builder with this patch applied, under a 11.3-STABLE jail and got:

running: /wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/build/aarch64-unknown-freebsd/stage0/bin/cargo build --manifest-path /wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/src/bootstrap/Cargo.toml --verbose --frozen
/wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/build/aarch64-unknown-freebsd/stage0/bin/cargo: Undefined symbol "lstat@FBSD_1.5"
Traceback (most recent call last):
  File "/wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/x.py", line 11, in <module>
    bootstrap.main()
  File "/wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/src/bootstrap/bootstrap.py", line 909, in main
    bootstrap(help_triggered)
  File "/wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/src/bootstrap/bootstrap.py", line 880, in bootstrap
    build.build_bootstrap()
  File "/wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/src/bootstrap/bootstrap.py", line 675, in build_bootstrap
    run(args, env=env, verbose=self.verbose)
  File "/wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/src/bootstrap/bootstrap.py", line 141, in run
    raise RuntimeError(err)
RuntimeError: failed to run: /wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/build/aarch64-unknown-freebsd/stage0/bin/cargo build --manifest-path /wrkdirs/usr/ports/lang/rust/work/rustc-1.40.0-src/src/bootstrap/Cargo.toml --verbose --frozen
*** Error code 1

Would it be possible to have a bootstrap compatible with FreeBSD 11?

In D23133#509306, @garga wrote:

Would it be possible to have a bootstrap compatible with FreeBSD 11?

You'll need to change _RUST_FBSD_VER_aarch64 to 11.3. Be aware that there are bugs in rtld on aarch64 11.3 (not sure if the bug is fixed in 11-stable), you'll need a ld-elf.so.1 from 12.1 or 12.stable (see bug https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=228892 for details)

@garga So is it ok for you now?

In D23133#511441, @tobik wrote:

@garga So is it ok for you now?

Unfortunately our ThunderX builder is out of service for maintenance and I won't be able to test it until next week. It is still broken for crossbuild, right?

In D23133#511524, @garga wrote:

In D23133#511441, @tobik wrote:

@garga So is it ok for you now?

Unfortunately our ThunderX builder is out of service for maintenance and I won't be able to test it until next week.

Ok. Let me know how it goes.

It is still broken for crossbuild, right?

Yes, unfortunately the build will just hang with qemu-user-static at some point.

It fails on armv6, 11.3-RELEASE. I used to build the bootstrap for 11.3, it's 12.1 with this port. I'm not against it but we should restrict lang/rust accordingly. I'd prefer keeping support for 11.3 though.

running: /usr/ports/lang/rust/work/rustc-1.41.0-src/build/armv6-unknown-freebsd/stage0/bin/cargo build --manifest-path /usr/ports/lang/rust/work/rustc-1.41.0-src/src/bootstrap/Cargo.toml --verbose --frozen
/usr/ports/lang/rust/work/rustc-1.41.0-src/build/armv6-unknown-freebsd/stage0/bin/cargo: Undefined symbol "lstat@FBSD_1.5"
/usr/ports/lang/rust/work/rustc-1.41.0-src/build/armv6-unknown-freebsd/stage0/bin/cargo: ELF 32-bit LSB shared object, ARM, EABI5 version 1 (FreeBSD), dynamically linked, interpreter /libexec/ld-elf.so.1, for FreeBSD 12.1, FreeBSD-style, with debug_info, not stripped

Something is odd, it seems the armv6 sysroot is for armv7:

readelf -A /usr/ports/lang/rust-bootstrap/work-armv6/lib/libcrypt.so.5
Attribute Section: aeabi
File Attributes
  Tag_CPU_arch: ARM v7
  Tag_CPU_arch_profile: Application Profile
  Tag_ARM_ISA_use: Yes
  Tag_THUMB_ISA_use: 32-bit Thumb
  Tag_FP_arch: VFPv3
  Tag_Advanced_SIMD_arch: NEONv1
  Tag_CPU_unaligned_access: Not allowed

Yeah, FreeBSD-11.3-RELEASE-arm-armv6.tar.xz and FreeBSD-12.1-RELEASE-arm-armv7.tar.xz were accidentally the same file... I'm rebuilding the armv6 bootstrap now.

In D23133#511525, @tobik wrote:

In D23133#511524, @garga wrote:

In D23133#511441, @tobik wrote:

@garga So is it ok for you now?

Unfortunately our ThunderX builder is out of service for maintenance and I won't be able to test it until next week.

Ok. Let me know how it goes.

It built fine! Thanks!

Can someone from portmgr approve the flavors? It would be nice if this could be committed before Rust 1.42.0 (2020-03-12).

Ping?

So, this needs lang/rust to build, and, lang/rust needs it to build? Isn't there some sort of circular dependency?

In D23133#523804, @mat wrote:

So, this needs lang/rust to build, and, lang/rust needs it to build? Isn't there some sort of circular dependency?

Yes, but there is no circular dependency in the ports tree sense. rust-bootstrap creates the bootstraps used for building the next stable release of lang/rust. I then upload the binaries somewhere before the next Rust release, so that lang/rust can fetch and use them. lang/rust will never depend directly on lang/rust-bootstrap.