objcopy: elf_begin() failed: Invalid argument

Hi

I'm trying to build the rust crate
https://github.com/alexcrichton/backtrace-rs
on 12-CURRENT.

World is most recent snapshot, kernel is drm-next which have been synced to
-HEAD at roughly the same time as world snapshot.

backtrace-rs builds a static c library, libbacktrace.a as a part of the
rust build process and I get the following error output on 12-CURRENT
(builds just fine on 11.0)


-- snip --

libtool: link: ranlib .libs/libbacktrace.a
libtool: link: ( cd ".libs" && rm -f "libbacktrace.la" && ln -s
"../libbacktrace.la" "libbacktrace.la" )
gmake[1]: Leaving directory
'/usr/home/johannes/dev/backtrace-rs/backtrace-sys/target/debug/build/backtrace-sys-816693a76d1c3a25/out'
cargo:rustc-link-search=native=/usr/home/johannes/dev/backtrace-rs/backtrace-sys/target/debug/build/backtrace-sys-816693a76d1c3a25/out/.libs
cargo:rustc-link-lib=static=backtrace
running: "ar" "x"
"/usr/home/johannes/dev/backtrace-rs/backtrace-sys/target/debug/build/backtrace-sys-816693a76d1c3a25/out/.libs/libbacktrace.a"
running: "objcopy" "--redefine-syms=symbol-map"
"/usr/home/johannes/dev/backtrace-rs/backtrace-sys/target/debug/build/backtrace-sys-816693a76d1c3a25/out/__tmp/"

--- stderr
objcopy: elf_begin() failed: Invalid argument
thread 'main' panicked at 'failed with: exit code: 1', build.rs:147:8
note: Run with `RUST_BACKTRACE=1` for a backtrace.



Github issue and full build output here:
https://github.com/alexcrichton/backtrace-rs/issues/56

Any ideas what has changed from 11->12 and how to deal with this change?


Thanks!