# Error in Building Rust with custom llvm-5.0

**URL:** <https://internals.rust-lang.org/t/error-in-building-rust-with-custom-llvm-5-0/8891>\
**Category:** compiler\
**Created:** [November 23, 2018, 12:44pm UTC](https://internals.rust-lang.org/t/error-in-building-rust-with-custom-llvm-5-0/8891 "2018-11-23T12:44:11Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![mananabdul](https://sea2.discourse-cdn.com/flex002/user_avatar/internals.rust-lang.org/mananabdul/32/4922_2.png) [@mananabdul](https://internals.rust-lang.org/u/mananabdul)\
**Post date:** [November 23, 2018, 12:44pm UTC](https://internals.rust-lang.org/t/error-in-building-rust-with-custom-llvm-5-0/8891/1 "2018-11-23T12:44:12Z")

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I am trying to build rust with LLVM-5.0, I first run this command: ./configure --llvm-root=/usr/lib/llvm-5.0

and then change codegen-tests to false in config.toml and run the following command: make && sudo make install

I am using latest git build…

Here is the terminal output with error:

Updating only changed submodules Submodules updated in 0.04 seconds downloading [https://static.rust-lang.org/dist/2018-10-30/rust-std-beta-x86\_64-unknown-linux-gnu.tar.gz](https://static.rust-lang.org/dist/2018-10-30/rust-std-beta-x86_64-unknown-linux-gnu.tar.gz) ######################################################################## 100.0% extracting /home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/cache/2018-10-30/rust-std-beta-x86\_64-unknown-linux-gnu.tar.gz downloading [https://static.rust-lang.org/dist/2018-10-30/rustc-beta-x86\_64-unknown-linux-gnu.tar.gz](https://static.rust-lang.org/dist/2018-10-30/rustc-beta-x86_64-unknown-linux-gnu.tar.gz) ######################################################################## 100.0% extracting /home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/cache/2018-10-30/rustc-beta-x86\_64-unknown-linux-gnu.tar.gz downloading [https://static.rust-lang.org/dist/2018-10-30/cargo-beta-x86\_64-unknown-linux-gnu.tar.gz](https://static.rust-lang.org/dist/2018-10-30/cargo-beta-x86_64-unknown-linux-gnu.tar.gz) ######################################################################## 100.0% extracting /home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/cache/2018-10-30/cargo-beta-x86\_64-unknown-linux-gnu.tar.gz Compiling proc-macro2 v0.4.24  
Compiling unicode-xid v0.1.0  
Compiling ryu v0.2.6  
Compiling serde v1.0.75  
Compiling ordermap v0.3.5  
Compiling cfg-if v0.1.5  
Compiling libc v0.2.43  
Compiling fixedbitset v0.1.9  
Compiling itoa v0.4.3  
Compiling cc v1.0.25  
Compiling lazy\_static v0.2.11  
Compiling build\_helper v0.1.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/build\_helper)  
Compiling getopts v0.2.17  
Compiling petgraph v0.4.13  
Compiling time v0.1.40  
Compiling num\_cpus v1.8.0  
Compiling filetime v0.2.1  
Compiling cmake v0.1.33  
Compiling quote v0.6.8  
Compiling syn v0.14.9  
Compiling serde\_derive v1.0.75  
Compiling toml v0.4.6  
Compiling serde\_json v1.0.31  
Compiling bootstrap v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/bootstrap)  
Finished dev [unoptimized] target(s) in 36.29s  
Downloaded rls-data v0.18.1  
Downloaded log v0.4.5  
Downloaded version\_check v0.1.5  
Downloaded openssl-sys v0.9.38  
Downloaded lazycell v1.2.0  
Downloaded libgit2-sys v0.7.10  
Downloaded ena v0.10.1  
Downloaded rustc-ap-rustc\_cratesio\_shim v297.0.0  
Downloaded openssl v0.10.13  
Downloaded proptest v0.8.7  
Downloaded rustc-ap-syntax\_pos v297.0.0  
Downloaded rustc-ap-graphviz v297.0.0  
Downloaded racer v2.1.13  
Downloaded wait-timeout v0.1.5  
Downloaded rls-vfs v0.7.0  
Downloaded socket2 v0.3.8  
Downloaded schannel v0.1.14  
Downloaded rustc-ap-serialize v297.0.0  
Downloaded syn v0.15.21  
Downloaded rls-analysis v0.16.8  
Downloaded rustc-ap-rustc\_data\_structures v297.0.0  
Downloaded crossbeam-channel v0.2.6  
Downloaded rustc-ap-rustc\_target v297.0.0  
Downloaded crossbeam-epoch v0.6.0  
Downloaded bytecount v0.3.2  
Downloaded minifier v0.0.20  
Downloaded simd v0.2.3  
Downloaded env\_logger v0.6.0  
Downloaded cargo\_metadata v0.6.2  
Downloaded derive\_more v0.13.0  
Downloaded rustc-ap-rustc\_errors v297.0.0  
Downloaded curl-sys v0.4.15  
Downloaded rustc-ap-syntax v297.0.0  
Downloaded git2-curl v0.8.2  
Downloaded pkg-config v0.3.14  
Downloaded winapi v0.3.6  
Downloaded bytesize v1.0.0  
Downloaded flate2 v1.0.3  
Downloaded rls-blacklist v0.1.3  
Downloaded rusty-fork v0.2.1  
Downloaded vergen v3.0.3  
Downloaded chalk-engine v0.8.0  
Downloaded compiletest\_rs v0.3.16  
Downloaded libz-sys v1.0.24  
Downloaded curl v0.4.19  
Downloaded bit-vec v0.5.0  
Downloaded libnghttp2-sys v0.1.0  
Downloaded bit-set v0.5.0  
Downloaded tar v0.4.19  
Downloaded rustc-ap-arena v297.0.0  
Downloaded crossbeam-utils v0.6.1  
Downloaded 51 crates (9.5 MB) in 14.84s (largest was `curl-sys` at 2.9 MB)  
Building stage0 std artifacts (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu)  
Compiling cc v1.0.25  
Compiling core v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libcore)  
Compiling build\_helper v0.1.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/build\_helper)  
Compiling unwind v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libunwind)  
Compiling compiler\_builtins v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/rustc/compiler\_builtins\_shim)  
Compiling cmake v0.1.33  
Compiling std v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libstd)  
Compiling rustc\_msan v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_msan)  
Compiling rustc\_asan v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_asan)  
Compiling rustc\_lsan v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_lsan)  
Compiling rustc\_tsan v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_tsan)  
Compiling libc v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/rustc/libc\_shim)  
Compiling alloc v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/liballoc)  
Compiling panic\_abort v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libpanic\_abort)  
Compiling panic\_unwind v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libpanic\_unwind)  
Finished release [optimized] target(s) in 25.68s  
Copying stage0 std from stage0 (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu / x86\_64-unknown-linux-gnu) Building stage0 test artifacts (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu) Compiling term v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libterm)  
Compiling getopts v0.2.17  
Compiling test v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libtest)  
Finished release [optimized] target(s) in 4.66s  
Copying stage0 test from stage0 (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu / x86\_64-unknown-linux-gnu) Building stage0 compiler artifacts (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu) Compiling version\_check v0.1.5  
Compiling nodrop v0.1.12  
Compiling cfg-if v0.1.5  
Compiling void v1.0.2  
Compiling scopeguard v0.3.3  
Compiling memoffset v0.2.1  
Compiling rand\_core v0.2.1  
Compiling libc v0.2.43  
Compiling stable\_deref\_trait v1.1.0  
Compiling rustc-rayon-core v0.1.1  
Compiling bitflags v1.0.4  
Compiling either v1.5.0  
Compiling unicode-width v0.1.5  
Compiling byteorder v1.2.3  
Compiling graphviz v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libgraphviz)  
Compiling rustc\_target v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_target)  
Compiling scoped-tls v0.1.2  
Compiling cc v1.0.25  
Compiling syntax v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libsyntax)  
Compiling termcolor v1.0.2  
Compiling lazy\_static v0.2.11  
Compiling rustc-demangle v0.1.9  
Compiling rustc v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc)  
Compiling datafrog v0.1.0  
Compiling remove\_dir\_all v0.5.1  
Compiling rustc\_fs\_util v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_fs\_util)  
Compiling fmt\_macros v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libfmt\_macros)  
Compiling rustc\_metadata v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_metadata)  
Compiling rustc\_incremental v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_incremental)  
Compiling rustc-serialize v0.3.24  
Compiling rustc\_platform\_intrinsics v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_platform\_intrinsics)  
Compiling quick-error v1.2.2  
Compiling rustc\_driver v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_driver)  
Compiling crossbeam-utils v0.2.2  
Compiling log v0.4.5  
Compiling arrayvec v0.4.7  
Compiling unreachable v1.0.0  
Compiling owning\_ref v0.3.3  
Compiling num\_cpus v1.8.0  
Compiling rand v0.5.5  
Compiling rand v0.4.3  
Compiling atty v0.2.11  
Compiling memmap v0.6.2  
Compiling lazy\_static v1.1.0  
Compiling rustc-hash v1.0.1  
Compiling chalk-macros v0.1.0  
Compiling humantime v1.1.1  
Compiling backtrace-sys v0.1.24  
Compiling miniz-sys v0.1.10  
Compiling ena v0.10.1  
Compiling rustc\_cratesio\_shim v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_cratesio\_shim)  
Compiling jobserver v0.1.11  
Compiling smallvec v0.6.5  
Compiling lock\_api v0.1.3  
Compiling tempfile v3.0.3  
Compiling rls-span v0.4.0  
Compiling polonius-engine v0.5.0  
Compiling chalk-engine v0.8.0  
Compiling env\_logger v0.5.12  
Compiling parking\_lot\_core v0.3.0  
Compiling serialize v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libserialize)  
Compiling rustc\_apfloat v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_apfloat)  
Compiling rls-data v0.18.1  
Compiling parking\_lot v0.6.4  
Compiling crossbeam-epoch v0.3.1  
Compiling log\_settings v0.1.2  
Compiling backtrace v0.3.9  
Compiling flate2 v1.0.3  
Compiling crossbeam-deque v0.2.0  
Compiling rustc-rayon v0.1.1  
Compiling rustc\_data\_structures v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_data\_structures)  
Compiling arena v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libarena)  
Compiling syntax\_pos v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libsyntax\_pos)  
Compiling rustc\_errors v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_errors)  
Compiling proc\_macro v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libproc\_macro)  
Compiling syntax\_ext v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libsyntax\_ext)  
Compiling rustc\_mir v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_mir)  
Compiling rustc\_typeck v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_typeck)  
Compiling rustc\_traits v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_traits)  
Compiling rustc\_allocator v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_allocator)  
Compiling rustc\_resolve v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_resolve)  
Compiling rustc\_plugin v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_plugin)  
Compiling rustc\_privacy v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_privacy)  
Compiling rustc\_codegen\_utils v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_codegen\_utils)  
Compiling rustc\_passes v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_passes)  
Compiling rustc\_borrowck v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_borrowck)  
Compiling rustc\_lint v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_lint)  
Compiling rustc\_save\_analysis v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_save\_analysis)  
Compiling rustc-main v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/rustc)  
Finished release [optimized] target(s) in 6m 59s  
Copying stage0 rustc from stage0 (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu / x86\_64-unknown-linux-gnu) Building stage0 codegen artifacts (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu, llvm) Compiling cc v1.0.25  
Compiling build\_helper v0.1.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/build\_helper)  
Compiling libc v0.2.43  
Compiling rustc-demangle v0.1.9  
Compiling rustc\_codegen\_llvm v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_codegen\_llvm)  
Compiling memmap v0.6.2  
Compiling num\_cpus v1.8.0  
Compiling rustc\_llvm v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_llvm)  
Compiling rustc\_codegen\_ssa v0.0.0 (/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/librustc\_codegen\_ssa)  
Finished release [optimized] target(s) in 42.34s  
Assembling stage1 compiler (x86\_64-unknown-linux-gnu) Building stage1 std artifacts (x86\_64-unknown-linux-gnu -\> x86\_64-unknown-linux-gnu) error: process didn’t exit successfully: `/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/bootstrap/debug/rustc -vV` (exit code: 1) — stdout rustc 1.32.0-dev binary: rustc commit-hash: unknown commit-date: unknown host: x86\_64-unknown-linux-gnu release: 1.32.0-dev

— stderr error: couldn’t load codegen backend “/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/x86\_64-unknown-linux-gnu/stage1/lib/rustlib/x86\_64-unknown-linux-gnu/codegen-backends/librustc\_codegen\_llvm-llvm.so”: “/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/x86\_64-unknown-linux-gnu/stage1/lib/rustlib/x86\_64-unknown-linux-gnu/codegen-backends/librustc\_codegen\_llvm-llvm.so: undefined symbol: ffi\_type\_float”

command did not execute successfully: “/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/x86\_64-unknown-linux-gnu/stage0/bin/cargo” “build” “–target” “x86\_64-unknown-linux-gnu” “-j” “4” “–release” “–features” “panic-unwind backtrace” “–manifest-path” “/home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/src/libstd/Cargo.toml” “–message-format” “json” expected success, got: exit code: 101 failed to run: /home/ab/Desktop/RUSTNightly/rust-master/GitHub/rust/build/bootstrap/debug/bootstrap build Build completed unsuccessfully in 0:18:09 Makefile:28: recipe for target ‘all’ failed make: \*\*\* [all] Error 1

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<div class="post-metadata">

**Author:** ![cuviper](https://sea2.discourse-cdn.com/flex002/user_avatar/internals.rust-lang.org/cuviper/32/1897_2.png) [@cuviper](https://internals.rust-lang.org/u/cuviper)\
**Post date:** [November 23, 2018, 6:59pm UTC](https://internals.rust-lang.org/t/error-in-building-rust-with-custom-llvm-5-0/8891/2 "2018-11-23T18:59:53Z")

</div>

Sounds like this: [https://github.com/rust-lang/rust/issues/39880](https://github.com/rust-lang/rust/issues/39880)

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<div class="post-metadata">

**Author:** ![system](https://sea2.discourse-cdn.com/flex002/user_avatar/internals.rust-lang.org/system/32/14092_2.png) [@system](https://internals.rust-lang.org/u/system)\
**Post date:** [March 25, 2019, 8:31am UTC](https://internals.rust-lang.org/t/error-in-building-rust-with-custom-llvm-5-0/8891/3 "2019-03-25T08:31:12Z")

</div>

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