rustup: 1.31.1 cannot be updated to via rustup on macos

[nagisa]

Similar issue to #57111 affects 1.31.1. Running rustup update fails to update the stable version of the compiler on my macos VM.

$ rustup update
info: syncing channel updates for 'stable-x86_64-apple-darwin'
info: latest update on 2018-12-20, rust version 1.31.1 (b6c32da9b 2018-12-18)
info: downloading component 'rustc'
 62.6 MiB /  62.6 MiB (100 %)   9.0 MiB/s ETA:   0 s                
info: downloading component 'rust-std'
 49.0 MiB /  49.0 MiB (100 %)   8.7 MiB/s ETA:   0 s                
info: downloading component 'cargo'
info: downloading component 'rust-docs'
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'cargo'
info: installing component 'rust-docs'
info: rolling back changes
error: could not rename component file from '/Users/nagisa/.rustup/tmp/u_96yv_zujys157v_dir/bk' to '/Users/nagisa/.rustup/toolchains/stable-x86_64-apple-darwin/share/man'
error: could not rename component file from '/Users/nagisa/.rustup/tmp/grcxr4i_29ol40_4_dir/bk' to '/Users/nagisa/.rustup/toolchains/stable-x86_64-apple-darwin/share/zsh'
error: could not rename component file from '/Users/nagisa/.rustup/tmp/pm8pirnch2ibpwx0_dir/bk' to '/Users/nagisa/.rustup/toolchains/stable-x86_64-apple-darwin/etc'
error: could not rename component file from '/Users/nagisa/.rustup/tmp/u3d1ccpi5umjpke6_dir/bk' to '/Users/nagisa/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin'
error: failed to install component: 'rust-docs-x86_64-apple-darwin', detected conflict: '"share/doc/rust/html"'

On my linux machine no such problem could be reproduced.

[clemensw]

Had no problem on mac, but similar problem on Linux for 1.31.1:
$ rustup update stable
info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
info: latest update on 2018-12-20, rust version 1.31.1 (b6c32da 2018-12-18)
info: downloading component 'rustc'
info: downloading component 'rust-std'
info: downloading component 'cargo'
info: downloading component 'rust-docs'
info: downloading component 'rust-analysis'
info: downloading component 'rls'
info: downloading component 'rustfmt'
info: downloading component 'rust-std' for 'asmjs-unknown-emscripten'
info: downloading component 'rust-src'
info: downloading component 'rust-std' for 'x86_64-unknown-linux-musl'
info: removing component 'rustc'
info: removing component 'rust-std'
info: removing component 'cargo'
info: removing component 'rust-docs'
info: removing component 'rust-analysis'
info: removing component 'rls'
info: removing component 'rustfmt'
info: removing component 'rust-std' for 'asmjs-unknown-emscripten'
info: removing component 'rust-src'
info: removing component 'rust-std' for 'x86_64-unknown-linux-musl'
info: installing component 'rustc'
info: rolling back changes
error: could not rename component file from '/home/clemens/.rustup/tmp/e2fw89j1wnis7cen_dir/bk' to '/home/clemens/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/share'
error: could not rename component file from '/home/clemens/.rustup/tmp/sm6nmf9auvwl_19d_dir/bk' to '/home/clemens/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/share/doc'
error: could not rename component file from '/home/clemens/.rustup/tmp/w6cn8xkriiy5yc07_dir/bk' to '/home/clemens/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu'
error: could not rename component file from '/home/clemens/.rustup/tmp/57a8mdwnj29qz900_dir/bk' to '/home/clemens/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/share/man'
error: failed to install component: 'rustc-x86_64-unknown-linux-gnu', detected conflict: '"lib/librustc-c0b0e3599e0c7f59.so"'

[Mark-Simulacrum]

I seem to have been able to update...

info: syncing channel updates for 'stable-x86_64-apple-darwin'
info: latest update on 2018-12-20, rust version 1.31.1 (b6c32da9b 2018-12-18)
info: downloading component 'rustc'
 62.6 MiB /  62.6 MiB (100 %)  14.7 MiB/s ETA:   0 s
info: downloading component 'rust-std'
 49.0 MiB /  49.0 MiB (100 %)  14.9 MiB/s ETA:   0 s
info: downloading component 'cargo'
info: downloading component 'rust-docs'
info: downloading component 'rustfmt'
info: removing component 'rustc'
info: removing component 'rust-std'
info: removing component 'cargo'
info: removing component 'rust-docs'
info: removing component 'rustfmt'
info: installing component 'rustc'
info: installing component 'rust-std'
info: installing component 'cargo'
info: installing component 'rust-docs'
info: installing component 'rustfmt'

  stable-x86_64-apple-darwin updated - rustc 1.31.1 (b6c32da9b 2018-12-18)

[nagisa]

I rolled the VM image back to what I had earlier today (banzai to the wonders of zfs!)

$ rustc +stable --version
rustc 1.31.0 (abe02cefd 2018-12-04)
$ rustup --version
rustup 1.16.0 (beab5ac2b 2018-12-06)
$ rustup show
Default host: x86_64-apple-darwin

installed toolchains
--------------------

stable-x86_64-apple-darwin
nightly-x86_64-apple-darwin (default)

installed targets for active toolchain
--------------------------------------

aarch64-apple-ios
armv7-apple-ios
i386-apple-ios
x86_64-apple-darwin
x86_64-apple-ios

active toolchain
----------------

nightly-x86_64-apple-darwin (default)
rustc 1.32.0-nightly (f4a421ee3 2018-12-13)

$ rustup update
# Fails exactly the same way as reported originally

[nagisa]

So at least the problem is reproducible, lmk if you need any other specific info to reproduce.

[Mark-Simulacrum]

Hm, okay -- unfortunately I am not on zfs so a similar rollback scheme wouldn't work here. I'm not sure what information would be needed additionally... the PR that caused the failure on nightly is almost certainly not the problem here as it's too recent (merged ~3 days ago)...

[nagisa]

From the output it feels like the root cause is the missing "removing component" part of the upgrade process.

[Mark-Simulacrum]

I'm going to go ahead and close this as I suspect it's extremely rare that this happens given that we haven't had other reports, if it is still a bug. Regardless it's probably in rustup, not the packaging scripts themselves, so should be filed there.