How to compile rust for mipsel-unknown-linux-uclibc ?

[nicolattuso]

Hi !
I tried to cross-compile rust for mipsel-unknown-linux-uclibc on my computer (x86_64-unknown-linux-gnu) following the instructions in commit 1cf9caf (@japaric) and failed. Here is what I did :
git checkout 2c6933acc (1.13.0)
I added the path to my mipsel toolchain (gcc, g++, ar, ...) to my PATH
./configure --enable-rustbuild --target=mipsel-unknown-linux-uclibc
make

Meta

➜  rust git:(2c6933a) rustc --version --verbose
rustc 1.13.0 (2c6933acc 2016-11-07)
binary: rustc
commit-hash: 2c6933acc05c61e041be764cb1331f6281993f3f
commit-date: 2016-11-07
host: x86_64-unknown-linux-gnu
release: 1.13.0

backtrace:

error: linking with `cc` failed: exit code: 1
  |
  = note: "cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-L" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/mipsel-unknown-linux-uclibc/lib" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o" "-o" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/libstd-c59cddcd0af2e166.so" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.metadata.o" "-Wl,-O1" "-nodefaultlibs" "-L" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps" "-L" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/build/std-a809d8d8110a0c2c/out/.libs" "-L" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/build/alloc_jemalloc-3fdf800200d00d2b/out/lib" "-L" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/build/compiler_builtins-6f98225e9c197338/out" "-L" "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/mipsel-unknown-linux-uclibc/lib" "-Wl,-Bstatic" "-Wl,--whole-archive" "-l" "backtrace" "-Wl,--no-whole-archive" "-Wl,-Bdynamic" "-l" "dl" "-l" "rt" "-l" "pthread" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/libpanic_unwind-7bbc0f7aeca8d97e.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/libcollections-2384fa75982df921.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/liballoc-97c94bbcbb6ce588.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/liballoc_jemalloc-d3ea7757ad00d487.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/librustc_unicode-0f8a4e3472bf9986.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/libunwind-a2900b506cabe0f1.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/liblibc-5e16cc1287996e06.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/librand-9e79fbad0cb1c989.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustc.bAZRRUAtC6j3/libcore-2bfca94c87453f15.rlib" "-Wl,--no-whole-archive" "/tmp/rustc.bAZRRUAtC6j3/libcompiler_builtins-66ce650a45b25434.rlib" "-l" "pthread" "-l" "gcc_s" "-l" "c" "-l" "m" "-l" "rt" "-l" "util" "-shared" "-Wl,-rpath,$ORIGIN/../lib"
  = note: /usr/bin/ld: /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: Relocations in generic ELF (EM: 8)
/usr/bin/ld: /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: Relocations in generic ELF (EM: 8)
/usr/bin/ld: /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: Relocations in generic ELF (EM: 8)
/usr/bin/ld: /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: Relocations in generic ELF (EM: 8)
/usr/bin/ld: /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: Relocations in generic ELF (EM: 8)
/usr/bin/ld: /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: Relocations in generic ELF (EM: 8)

... <many more similar messages>

/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: error adding symbols: File in wrong format
collect2: error: ld returned 1 exit status


error: aborting due to previous error

error: Could not compile `std`.

To learn more, run the command again with --verbose.


command did not execute successfully: "/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "build" "-j" "8" "--target" "mipsel-unknown-linux-uclibc" "--release" "--features" " jemalloc backtrace" "--manifest-path" "/mnt/ssd/rust/rust/src/rustc/std_shim/Cargo.toml"
expected success, got: exit code: 101


Makefile:23: recipe for target 'all' failed
make: *** [all] Error 1

➜  rust git:(2c6933a) file /mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o
/mnt/ssd/rust/rust/build/x86_64-unknown-linux-gnu/stage2-std/mipsel-unknown-linux-uclibc/release/deps/std-c59cddcd0af2e166.0.o: ELF 32-bit LSB relocatable, MIPS, MIPS32 version 1 (SYSV), not stripped

[m4b]

You need a linker that understands MIPS relocations. In general, any time your target architecture (first thing in triple) is not your host architecture, you need to pass a different linker.

I've never built for MIPS but looks like you're using system linker /usr/bin/ld; try passing default linker (and default ar) the path to your MIPS linker, but that might cause bootstrapping problems, dunno.

@japaric will know better

[nicolattuso]

Thank you for your answer, indeed the build system used cc to try to link the object files compiled with mipsel-unknown-linux-uclibc-gcc.
I did not find how to pass the correct linker to the build system. How can I do that ?

[japaric]

@nicolattuso You'll probably have to set all these environment variables:

$ export AR_mipsel_unknown_linux_uclibc=mipsel-unknown-linux-uclibc-ar
$ export CC_mipsel_unknown_linux_uclibc=mipsel-unknown-linux-uclibc-gcc
$ export CXX_mipsel_unknown_linux_uclibc=mipsel-unknown-linux-uclibc-g++
$ export CARGO_TARGET_MIPSEL_UNKNOWN_LINUX_UCLIBC_LINKER=mipsel-unknown-linux-uclibc-gcc

And also delete the C libraries in the build directory (because they likely were compiled with the wrong compiler i.e. cc). I think rm -rf build/**/x86_64-unknown-linux-musl should do that.

Before you call make / x.py again.

[Mark-Simulacrum]

The steps above should be helpful. Seeing as there's no further comments from @nicolattuso I'm going to take the assumption that they're either not interested or these steps worked, so closing.