New rustc nightly with llvm-10 breaks script_plugins

[jdm]

error: linking with `cc` failed: exit code: 1
  |
  = note: "cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-m64" "-L" "/root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.0.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.1.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.10.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.11.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.12.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.13.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.14.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.15.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.2.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.3.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.4.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.5.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.6.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.7.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.8.rcgu.o" "/repo/target/debug/deps/script_plugins.script_plugins.blvvqtbe-cgu.9.rcgu.o" "-o" "/repo/target/debug/deps/libscript_plugins.so" "-Wl,--version-script=/tmp/rustczV5bvX/list" "/repo/target/debug/deps/script_plugins.a9q7pget1xzpz9k.rcgu.o" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/repo/target/debug/deps" "-L" "/root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-L" "/root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-lrustc_driver-fefef43299f39010" "-Wl,--start-group" "-L" "/root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-lstd-265ff16c7b6b86f9" "-Wl,--end-group" "-Wl,-Bstatic" "/tmp/rustczV5bvX/libcompiler_builtins-a1755b3e88842f5d.rlib" "-Wl,-Bdynamic" "-lLLVM-10-rust-1.45.0-nightly" "-lutil" "-ldl" "-lutil" "-ldl" "-lrt" "-lpthread" "-lgcc_s" "-lc" "-lm" "-lrt" "-lpthread" "-lutil" "-ldl" "-lutil" "-shared" "-fuse-ld=gold"
  = note: /usr/bin/ld.gold: error: cannot find -lLLVM-10-rust-1.45.0-nightly
          collect2: error: ld returned 1 exit status
          
error: aborting due to previous error
error: could not compile `script_plugins`.

This might be something we need to report upstream.

[jdm]

cc @SimonSapin

[jdm]

Filed upstream as rust-lang/rust#72594.

[SimonSapin]

As suggested in rust-lang/rust#72594 (comment), rustup component add llvm-tools-preview seems to fix this. We should be able to add it next to rustc-dev here:

servo/python/servo/command_base.py

Lines 989 to 991 in a344657

	for component in set(rustup_components or []) | {"rustc-dev"}:
	if component.encode("utf-8") not in installed:
	check_call(["rustup", "component", "add", "--toolchain", toolchain, component])