Hi,

so after our mrustc upgrade to 0.9, we get the following when building rust 1.19.0
on guix master 4de63cf3fc0a831d75cb507456821104f24800c2 and i686-linux:

[...]
(75/77) BUILDING git2_curl from git2-curl v0.7.0
> /gnu/store/0hzdzb07gaplh2x96mg7dpvip92shx43-mrustc-0.9/bin/mrustc src/vendor/git2-curl/src/lib.rs -o output/cargo-build/libgit2_curl-0_7_0.rlib --crate-name git2_curl --crate-type rlib -C emit-depfile=output/cargo-build/libgit2_curl-0_7_0.rlib.d --crate-tag 0_7_0 -g --cfg debug_assertions -O -L output -L /gnu/store/0hzdzb07gaplh2x96mg7dpvip92shx43-mrustc-0.9/lib/mrust -L output/cargo-build --extern curl=output/cargo-build/libcurl-0_4_6.rlib --extern url=output/cargo-build/liburl-1_4_0.rlib --extern log=output/cargo-build/liblog-0_3_7.rlib --extern git2=output/cargo-build/libgit2-0_6_6.rlib
(76/77) BUILDING cargo v0.20.0
> /gnu/store/0hzdzb07gaplh2x96mg7dpvip92shx43-mrustc-0.9/bin/mrustc src/tools/cargo/src/cargo/lib.rs -o output/cargo-build/libcargo-0_20_0.rlib --crate-name cargo --crate-type rlib -C emit-depfile=output/cargo-build/libcargo-0_20_0.rlib.d --crate-tag 0_20_0 -g --cfg debug_assertions -O -L output -L /gnu/store/0hzdzb07gaplh2x96mg7dpvip92shx43-mrustc-0.9/lib/mrust -L output/cargo-build --extern crates_io=output/cargo-build/libcrates_io-0_9_0.rlib --extern crossbeam=output/cargo-build/libcrossbeam-0_2_10.rlib --extern curl=output/cargo-build/libcurl-0_4_6.rlib --extern docopt=output/cargo-build/libdocopt-0_7_0.rlib --extern env_logger=output/cargo-build/libenv_logger-0_4_2.rlib --extern error_chain=output/cargo-build/liberror_chain-0_10_0.rlib --extern filetime=output/cargo-build/libfiletime-0_1_10.rlib --extern flate2=output/cargo-build/libflate2-0_2_19.rlib --extern fs2=output/cargo-build/libfs2-0_4_1.rlib --extern git2=output/cargo-build/libgit2-0_6_6.rlib --extern git2_curl=output/cargo-build/libgit2_curl-0_7_0.rlib --extern glob=output/cargo-build/libglob-0_2_11.rlib --extern jobserver=output/cargo-build/libjobserver-0_1_6.rlib --extern libc=output/cargo-build/liblibc-0_2_22.rlib --extern libgit2_sys=output/cargo-build/liblibgit2_sys-0_6_12.rlib --extern log=output/cargo-build/liblog-0_3_7.rlib --extern num_cpus=output/cargo-build/libnum_cpus-1_4_0.rlib --extern rustc_serialize=output/cargo-build/librustc_serialize-0_3_24.rlib --extern scoped_tls=output/cargo-build/libscoped_tls-0_1_0.rlib --extern semver=output/cargo-build/libsemver-0_7_0.rlib --extern serde=output/cargo-build/libserde-1_0_6.rlib --extern serde_derive=output/cargo-build/libserde_derive-1_0_6-plugin --extern serde_ignored=output/cargo-build/libserde_ignored-0_0_3.rlib --extern serde_json=output/cargo-build/libserde_json-1_0_2.rlib --extern shell_escape=output/cargo-build/libshell_escape-0_1_3.rlib --extern tar=output/cargo-build/libtar-0_4_13.rlib --extern tempdir=output/cargo-build/libtempdir-0_3_5.rlib --extern term=output/cargo-build/libterm-0_4_5.rlib --extern toml=output/cargo-build/libtoml-0_4_1.rlib --extern url=output/cargo-build/liburl-1_4_0.rlib --extern openssl=output/cargo-build/libopenssl-0_9_12.rlib
BUILDING cargo v0.20.0
> /gnu/store/0hzdzb07gaplh2x96mg7dpvip92shx43-mrustc-0.9/bin/mrustc src/tools/cargo/src/bin/cargo.rs -o output/cargo-build/cargo --crate-name cargo --crate-type bin -C emit-depfile=output/cargo-build/cargo.d --crate-tag 0_20_0 -g --cfg debug_assertions -O -L output -L /gnu/store/0hzdzb07gaplh2x96mg7dpvip92shx43-mrustc-0.9/lib/mrust -L output/cargo-build --extern cargo=output/cargo-build/libcargo-0_20_0.rlib --extern crates_io=output/cargo-build/libcrates_io-0_9_0.rlib --extern crossbeam=output/cargo-build/libcrossbeam-0_2_10.rlib --extern curl=output/cargo-build/libcurl-0_4_6.rlib --extern docopt=output/cargo-build/libdocopt-0_7_0.rlib --extern env_logger=output/cargo-build/libenv_logger-0_4_2.rlib --extern error_chain=output/cargo-build/liberror_chain-0_10_0.rlib --extern filetime=output/cargo-build/libfiletime-0_1_10.rlib --extern flate2=output/cargo-build/libflate2-0_2_19.rlib --extern fs2=output/cargo-build/libfs2-0_4_1.rlib --extern git2=output/cargo-build/libgit2-0_6_6.rlib --extern git2_curl=output/cargo-build/libgit2_curl-0_7_0.rlib --extern glob=output/cargo-build/libglob-0_2_11.rlib --extern jobserver=output/cargo-build/libjobserver-0_1_6.rlib --extern libc=output/cargo-build/liblibc-0_2_22.rlib --extern libgit2_sys=output/cargo-build/liblibgit2_sys-0_6_12.rlib --extern log=output/cargo-build/liblog-0_3_7.rlib --extern num_cpus=output/cargo-build/libnum_cpus-1_4_0.rlib --extern rustc_serialize=output/cargo-build/librustc_serialize-0_3_24.rlib --extern scoped_tls=output/cargo-build/libscoped_tls-0_1_0.rlib --extern semver=output/cargo-build/libsemver-0_7_0.rlib --extern serde=output/cargo-build/libserde-1_0_6.rlib --extern serde_derive=output/cargo-build/libserde_derive-1_0_6-plugin --extern serde_ignored=output/cargo-build/libserde_ignored-0_0_3.rlib --extern serde_json=output/cargo-build/libserde_json-1_0_2.rlib --extern shell_escape=output/cargo-build/libshell_escape-0_1_3.rlib --extern tar=output/cargo-build/libtar-0_4_13.rlib --extern tempdir=output/cargo-build/libtempdir-0_3_5.rlib --extern term=output/cargo-build/libterm-0_4_5.rlib --extern toml=output/cargo-build/libtoml-0_4_1.rlib --extern url=output/cargo-build/liburl-1_4_0.rlib --extern openssl=output/cargo-build/libopenssl-0_9_12.rlib
"libcore"
command "output/rustc-build/rustc" "-C" "linker=/gnu/store/y7dd2178bbpy7pl09fdn1r9412rc2mm3-gcc-7.4.0/bin/gcc" "-Z" "force-unstable-if-unmarked" "-L" "output/target-libs" "src/libcore/lib.rs" "-o" "output/target-libs/libcore.rlib" failed with signal 8

That's extremely good, but signal 8 is SIGFPE, as before.