error: unable to run rust-objcopy: No such file or directory (os error 2)

[onur-ozkan]

As we install rust-objcopy conditionally on dist step

rust/src/bootstrap/src/core/build_steps/dist.rs

Lines 475 to 480 in 1ab85fb

	if builder.config.llvm_enabled(compiler.host) && builder.config.llvm_tools_enabled {
	let src_dir = builder.sysroot_target_bindir(compiler, host);
	let llvm_objcopy = exe("llvm-objcopy", compiler.host);
	let rust_objcopy = exe("rust-objcopy", compiler.host);
	builder.copy_link(&src_dir.join(&llvm_objcopy), &dst_dir.join(&rust_objcopy));
	}

using external LLVM with llvm-tools set to false causes the toolchain built from bootstrap to fail when compiling programs due to the missing rust-objcopy.

We should be capable of checking for the external LLVM's tools and installing them. If these tools don't exist, the build should terminate (so it doesn't waste hours of time on building) with an error message.

[onur-ozkan]

Turns out this isn't the case.. See #135356 (comment).

[debohman]

As I commented in #135356, setting llvm-tools=true when building with a system LLVM does not install rust-objcopy into the destination root.

[onur-ozkan]

I tried it multiple times and it worked fine on each try.

[llvm]
download-ci-llvm=false

[rust]
download-rustc = false
llvm-tools = true

[target.x86_64-unknown-linux-gnu]
llvm-config = "/home/nimda/devspace/llvm-19/bin/llvm-config"

I invoked DESTDIR=./demo ./x.py install command on 1.84.0 stable tarball source using the config above, here is the result:

$ ~/downloads/rustc-1.84.0-src  $ ls -lah ./demo/usr/local/lib/rustlib/x86_64-unknown-linux-gnu/bin
total 6.7M
drwxr-xr-x 2 nimda nimda 4.0K Jan 16 15:38 .
drwxr-xr-x 4 nimda nimda 4.0K Jan 16 15:38 ..
-rwxr-xr-x 1 nimda nimda 6.7M Jan 16 15:38 rust-objcopy

rust-objcopy is installed from the external LLVM (which is /home/nimda/devspace/llvm-19) as expected.