The version of LLVM-7 in Debian unstable breaks rustc currently. Can you try it with the LLVM-7 from Debian testing? i.e. this one:
$ apt-cache policy llvm-7 llvm-7: Installed: 1:7-6 Candidate: 1:7-6 Version table: 1:7.0.1~+rc2-2 300 300 http://deb.debian.org/debian unstable/main amd64 Packages *** 1:7-6 990 990 http://deb.debian.org/debian testing/main amd64 Packages 100 /var/lib/dpkg/status X brian m. carlson: > Package: rustc > Version: 1.30.0+dfsg1-2 > Severity: important > > If you attempt to build a release binary, rustc fails because of a bad > relocation when making a PIE object. > > Steps to reproduce: > 1. git clone https://github.com/rust-lang-nursery/rust-clippy.git > 2. cd rust-clippy > 3. git checkout v0.0.212 > 4. cargo build --verbose --release > 5. Notice that the build fails. > 6. Notice messages like the following: > > = note: /usr/bin/ld: > /home/bmc/checkouts/external/rust-clippy/target/release/build/serde-3ddadc5e75c3de00/build_script_build-3ddadc5e75c3de00.build_script_build.140spq3r-cgu.2.rcgu.o: > relocation R_X86_64_32S against `.rodata.cst16' can not be used when making > a PIE object; recompile with -fPIC > /usr/bin/ld: > /home/bmc/checkouts/external/rust-clippy/target/release/build/serde-3ddadc5e75c3de00/build_script_build-3ddadc5e75c3de00.build_script_build.140spq3r-cgu.4.rcgu.o: > relocation R_X86_64_32 against symbol `rust_eh_personality' can not be used > when making a PIE object; recompile with -fPIC > /usr/bin/ld: > /home/bmc/checkouts/external/rust-clippy/target/release/build/serde-3ddadc5e75c3de00/build_script_build-3ddadc5e75c3de00.build_script_build.140spq3r-cgu.6.rcgu.o: > relocation R_X86_64_32 against symbol `rust_eh_personality' can not be used > when making a PIE object; recompile with -fPIC > /usr/bin/ld: > /home/bmc/checkouts/external/rust-clippy/target/release/build/serde-3ddadc5e75c3de00/build_script_build-3ddadc5e75c3de00.build_script_build.140spq3r-cgu.9.rcgu.o: > relocation R_X86_64_32 against symbol `rust_eh_personality' can not be used > when making a PIE object; recompile with -fPIC > /usr/bin/ld: final link failed: nonrepresentable section on output > collect2: error: ld returned 1 exit status > > I see similar errors on a project of my own which compiled fine on > November 3. I also see this failure with rust 1.31.0 beta from > experimental. > > -- System Information: > Debian Release: buster/sid > APT prefers unstable-debug > APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'stable'), > (1, 'experimental-debug'), (1, 'experimental') > Architecture: amd64 (x86_64) > Foreign Architectures: i386 > > Kernel: Linux 4.18.0-2-amd64 (SMP w/4 CPU cores) > Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), > LANGUAGE=en_US.UTF-8 (charmap=UTF-8) > Shell: /bin/sh linked to /bin/dash > Init: systemd (via /run/systemd/system) > LSM: AppArmor: enabled > > Versions of packages rustc depends on: > ii binutils 2.31.1-7 > ii gcc 4:8.2.0-2 > ii libc6 2.27-8 > ii libc6-dev [libc-dev] 2.27-8 > ii libgcc1 1:8.2.0-9 > ii libllvm7 1:7.0.1~+rc2-2 > ii libstd-rust-dev 1.30.0+dfsg1-2 > ii libstdc++6 8.2.0-9 > > Versions of packages rustc recommends: > ii cargo 0.31.0-2 > ii rust-gdb 1.30.0+dfsg1-2 > > Versions of packages rustc suggests: > ii rust-doc 1.30.0+dfsg1-2 > pn rust-src <none> > > -- no debconf information > -- GPG: ed25519/56034877E1F87C35 GPG: rsa4096/1318EFAC5FBBDBCE https://github.com/infinity0/pubkeys.git