On linker errors write command to file instead of printing to disk

[estebank]

Current output

error: linking with `cc` failed: exit status: 1
    |
    = note: LC_ALL="C" PATH="/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/bin:/Users/noahkelly/.cabal/bin:/Users/noahkelly/.ghcup/bin:/Users/noahkelly/.cargo/bin:/Library/Frameworks/Python.framework/Versions/3.10/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/noahkelly/Downloads/apache-maven-3.8.2/bin:/usr/local/share/dotnet:/opt/X11/bin:~/.dotnet/tools:/Applications/Wireshark.app/Contents/MacOS:/Users/noahkelly/.cargo/bin" VSLANG="1033" ZERO_AR_DATE="1" "cc" "-arch" "x86_64" "-m64" "/var/folders/9t/1d02qjxd6rd_2vrpg1_fd1y80000gn/T/rustcQswpeL/symbols.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.12hqyt5gjqwogg3l.rcgu.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.170m4bx95h60hgxl.rcgu.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.2htc2bizz0xlomh4.rcgu.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.32t7xrbq5e59nsg3.rcgu.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.4ffg2fgund0et5fl.rcgu.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.57snssrffpftjrce.rcgu.o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391.20k16tb80xbjiv8t.rcgu.o" "-L" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps" "-L" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libstd-8c7ba4cb14921aed.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libpanic_unwind-90e9ca565b042945.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libobject-464a0586d0933b26.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libmemchr-db3d1e5a32355b36.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libaddr2line-74798b95a0884a59.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libgimli-d7b0a7d172fdaf84.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/librustc_demangle-c50e314035d07ff6.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libstd_detect-ed447ed716cd0465.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libhashbrown-4f8aa5a213a4f4a6.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libminiz_oxide-2c711c9d26ddd542.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libadler-ab666c0d9447875d.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/librustc_std_workspace_alloc-711ae8c2777323b0.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libunwind-dac435ef9b9ec5bd.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libcfg_if-16d13d5a3e9202fe.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/liblibc-6817e59b6d2f2f20.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/liballoc-316b477d50fb0f01.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/librustc_std_workspace_core-7ba55cce4735e904.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libcore-399e1f4c06861f02.rlib" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib/libcompiler_builtins-8bb525c7516034b0.rlib" "-lSystem" "-lc" "-lm" "-L" "/Users/noahkelly/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/lib" "-o" "/Users/noahkelly/Desktop/CAIS_0302/Presentation2/tutorials/rust_tutorial/target/debug/deps/rust_tutorial-82284bbf181b6391" "-Wl,-dead_strip" "-nodefaultlibs"  
    = note: xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
error

Desired output

error: linking with `cc` failed: exit status: 1
    |
    = note: executed command written to `/Users/noahkelly/command.txt`
    = note: xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun
error

Rationale and extra context

Linker errors print the entire command that was executed before printing the output of the command. This is very useful to debug why the error occurred, but it obscures the executed command's explanation of the situation. We already print files to disk for really long paths, we should do the same for really long commands.

Anything else?

filed on behalf of https://www.reddit.com/r/rust/comments/12x2fg6/cant_run_hello_world/

[Mark-Simulacrum]

My worry is that this makes it ~impossible to debug such errors if they occur in CI systems or elsewhere where that file would now be lost. I'm not sure if we already have a solution there (read $CI, at minimum?) but I think it's a real pain point.

I do think at minimum we should de-emphasize the wall of text - I wonder if there's any kind of terminal magic that might help there, similar to <details> on the web.

[jyn514]

cc #109979

[estebank]

@Mark-Simulacrum regarding CI, it has come up multiple times now that what is ideal for interactive terminals and what is ideal to debug CI output after the fact differs in exactly this way. That tells me we should bite the bullet and provide an env flag to tweak the output in a single place (and make the CI one the default, advertise how to set up the more user friendly version in rustup).

[Mark-Simulacrum]

Definitely +1 to that, I think there's other things that may want a different default too (e.g., cargo may want to dump future incompat for similar reasons, we may not want to be incremental by default, etc.)