cargo install exits with success code on partial failures

[horacimacias]

Problem
cargo install exits with success code when installing a list of crates, even if some of them failed.
As a result, anybody running cargo install crate1 crate2 will get a false sense of success if one of the crates failed to install. For example Dockerfiles running such commands will not fail to build, which means the resulting container image does not contain all the crates one hopes to find installed, since cargo install still exited with success code.

Steps

1. cargo install a list of crates where at least 1 fails and at least 1 succeeds. Right now I used cargo install --force cargo-sweep cargo-deny for example (as cargo-deny has issues installing without --locked; see Build failure due to bitvec dependency EmbarkStudios/cargo-deny#331 for details although the reason for failure is irrelevant to the issue reported here)
2. Check the last command exit code. it should be non-zero but it is zero.

Possible Solution(s)
Perhaps it's better to succeed only if all requested crates were successfully installed.
As a side note, documentation for cargo install should be updated to reflect the behaviour, either current or future.

Notes

Output of cargo version:

cargo 1.49.0 (d00d64d 2020-12-05)
OSX using stable channel

[ehuss]

Hm, I just ran cargo install cargo-sweep cargo-deny and got this output:

~> cargo install cargo-sweep cargo-deny
...snip...

error: could not compile `bitvec`

To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: failed to compile `cargo-deny v0.8.6`, intermediate artifacts can be found at `/var/folders/rw/vx9xfxys6kjd5x1jw70pqg2c0000gn/T/cargo-installAvdwDX`

Caused by:
  build failed
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
warning: be sure to add `./bin` to your PATH to be able to run the installed binaries
error: some crates failed to install
~> echo $?
101

The important part is at the end error: some crates failed to install, and it exits with 101. Did you not get that error message? Can you show a reproduction where the exit code is nonzero?

[horacimacias]

thanks for looking at this.
It's weird; for me I'm getting a 0 status code.
I'm usually running fish shell v3.1.2 on OSX but I also tried bash on OSX and bash on linux; same results for me.

fish on OSX (it uses $status instead of $?):

Caused by:
  build failed
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
⋊> echo $status                                                                                                                                                                                                                                             
0

I also combined the command with "echo yes" and I see the echoed message:

cargo install cargo-sweep cargo-deny; and echo yes
....
Caused by:
  build failed
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
yes

we can ignore fish if that's not common enough.
I tried same thing in bash on OSX:

Caused by:
  build failed
     Ignored package `cargo-sweep v0.5.0` is already installed, use --force to override
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
computer:workspace hmacias$ echo $?
0
computer:workspace hmacias$ cargo version
cargo 1.49.0 (d00d64df9 2020-12-05)

and I also tried cargo install cargo-deny cargo-sweep && echo yes:

Caused by:
  build failed
     Ignored package `cargo-sweep v0.5.0` is already installed, use --force to override
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
yes

and finally cargo install cargo-deny cargo-sweep on bash's linux:

Caused by:
  build failed
     Ignored package `cargo-sweep v0.5.0` is already installed, use --force to override
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
[root@linpubab062 ~]# echo $?
0
[root@linpubab062 ~]# cargo version
cargo 1.45.0 (744bd1fbb 2020-06-15)
[root@linpubab062 ~]# cat /etc/redhat-release 
CentOS Linux release 7.9.2009 (Core)

Running cargo install cargo-deny cargo-sweep && echo yes also printed 'yes'

I'm running out of ideas, everything I try seems to indicate the command is exiting with status code 0?

[horacimacias]

tried deleting cargo-sweep in case this being already installed has any relation to things but no difference:

error: failed to compile `cargo-deny v0.8.6`, intermediate artifacts can be found at `/tmp/cargo-installT2EqzG`

Caused by:
  build failed
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
yes

[horacimacias]

in case this is relevant, I see you're getting a error: some crates failed to install but I'm not.

We both see the Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above). but I'm not seeing the error: some crates failed to install anywhere 🤷

[horacimacias]

last attempt using an official docker image, in case the problem is with my setup.
This is the Dockerfile:

FROM rust:1.50.0

RUN cargo install cargo-sweep cargo-deny && echo $?

docker build . runs successfully (I'd expect it to fail) and the $? prints 0:

Caused by:
  build failed
     Summary Successfully installed cargo-sweep! Failed to install cargo-deny (see error(s) above).
0
Removing intermediate container 11e8dbb05051
 ---> 16a0e8108c9a
Successfully built 16a0e8108c9a

[ehuss]

My apologies, I see what is wrong. If the destination is in PATH, it is exiting prematurely. This line needs to change.

[horacimacias]

thanks! let's see if this PR helps.