How to rustup update when permission is denied?

Question

When I ran rustup update, I got the following error:

info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
error: could not create temp file /home/abc/.rustup/tmp/mbbafo7rtfs5aazi_file
info: checking for self-updates

  stable-x86_64-unknown-linux-gnu update failed - rustc 1.52.1 (9bc8c42bb 2021-05-09)

info: cleaning up downloads & tmp directories
thread 'main' panicked at 'Unable to clean up /home/abc/.rustup/downloads: Os { code: 13, kind: PermissionDenied, message: "Permission denied" }', src/utils/utils.rs:642:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Then, I tried to run sudo rustup update and got the following:

sudo: rustup: command not found

The output of ls -l /home/abc/.rustup/ is:

total 28
drwxr-xr-x 2 root root 4096 May 31 14:06 downloads
-rw-r--r-- 1 root root  102 May 31 14:06 settings.toml
drwxr-xr-x 2 root root 4096 May 31 14:06 tmp
drwxr-xr-x 3 root root 4096 May 31 14:06 toolchains
drwxr-xr-x 2 root root 4096 May 31 14:06 update-hashes

Answer 1

It looks like you installed the Rust toolchain using the root account. This can be fixed by changing the user and group permissions of .rustup.

sudo chown -R abc:abc /home/abc/.rustup
rustup update

If your /home/abc/.cargo is also owned by root you will probably want to fix that too.