unhelpful error message trying to uninstall ambiguous crate name

[matthiaskrgr]

cargo 0.26.0-nightly (1d6dfea44 2018-01-26)
rustc 1.25.0-nightly (3d292b793 2018-02-03)

I have a rustfmt-nightly installed in $CARGO_HOME.
I tried to remove it:

cargo uninstall rustfmt-nightly 

error: There are multiple `rustfmt-nightly` packages in your project, and the specification `rustfmt-nightly` is ambiguous.
Please re-run this command with `-p <spec>` where `<spec>` is one of the following:
  rustfmt-nightly:0.3.4
  rustfmt-nightly:0.3.8

The error message is confusing, according to cargo help uninstall, -p is not even a valid option for uninstall

I tried a couple of things

cargo uninstall  -p "rustfmt-nightly:0.3.4" 
cargo  -p "rustfmt-nightly:0.3.4" uninstall
cargo uninstall rustfmt-nightly -p "rustfmt-nightly:0.3.4" 

but none of these worked.

EDIT:
Hmm, I found this in my $CARGO_HOME/.crates.toml

"rustfmt-nightly 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = ["git-fmt"]
"rustfmt-nightly 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = ["cargo-fmt", "git-rustfmt", "rustfmt", "rustfmt-format-diff"]

[matthiaskrgr]

Hmm, I think the underlying problem is that rustfmt changed the name of its executable which might have confused cargo.
rust-lang/rustfmt@361a30b#diff-80398c5faae3c069e4e6aa2ed11b28c0
While upgrading from one version to another, cargo apparently did not remove the old binary properly so I ended up with orphaned executables, I guess.

EDIT: I can confirm via local testcase:

cargo installing

[package]
name = "cargo_test"
version = "0.1.0"

[dependencies]

[[bin]]
name = "test_1"
path = "src/main.rs"

, and then changing version and path

[package]
name = "cargo_test"
version = "0.2.0"

[dependencies]

[[bin]]
name = "test_2"
path = "src/main.rs"

and installing again will leave the old binary in place.

"cargo_test 0.1.0 (path+file:///tmp/cargo_test)" = ["test_1"]
"cargo_test 0.2.0 (path+file:///tmp/cargo_test)" = ["test_2"]

Uninstalling via
cargo uninstall cargo_test:0.1.0
cargo uninstall cargo_test:0.2.0
worked, so it seems the -p is simply wrong.

[seanmonstar]

To clarify, this issue is that the help text from cargo uninstall foo is incorrect if the spec is ambiguous. It suggests running cargo uninstall -p foo:1.2.3, when really you run cargo uninstall foo:1.2.3.

A fix to this issue would be removing the -p <spec> part of the help text.

[skyfaller]

I just ran into this bug on macOS Catalina 10.15.7 running the current cargo from homebrew:

> cargo install-update -a                                                                                                                                                
    Updating registry 'https://github.com/rust-lang/crates.io-index'

Package       Installed  Latest  Needs update
bk            v0.5.3     v0.5.3  No
cargo-update  v7.0.1     v7.0.1  No
dijo          v0.2.7     v0.2.7  No
kalk_cli      v0.5.4     v0.5.4  No
ncgopher      v0.2.0     v0.2.0  No
rtw           v2.3.0     v2.3.0  No
zee           v0.1.2     v0.1.2  No

No packages need updating.
Overall updated 0 packages.
> cargo uninstall kalk_cli                                                                                                                                               
error: There are multiple `kalk_cli` packages in your project, and the specification `kalk_cli` is ambiguous.
Please re-run this command with `-p <spec>` where `<spec>` is one of the following:
  kalk_cli:0.1.8
  kalk_cli:0.5.4
> cargo uninstall kalk_cli:0.1.8                                                                                                                                         
    Removing /Users/nelson/.cargo/bin/kalk_cli
> cargo uninstall kalk_cli:0.5.4                                                                                                                                         
    Removing /Users/nelson/.cargo/bin/kalk
> cargo --version                                                                                                                                                        
cargo 1.56.0
> brew info rust                                                                                                                                                         
rust: stable 1.56.0 (bottled), HEAD
Safe, concurrent, practical language
https://www.rust-lang.org/
/usr/local/Cellar/rust/1.56.0 (30,734 files, 763.3MB) *
  Poured from bottle on 2021-10-26 at 12:00:13
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/rust.rb
License: Apache-2.0 or MIT
==> Dependencies
Build: cmake ✘, ninja ✘, python@3.9 ✔
Required: libssh2 ✔, openssl@1.1 ✔, pkg-config ✔
==> Options
--HEAD
	Install HEAD version
==> Analytics
install: 28,991 (30 days), 93,440 (90 days), 289,660 (365 days)
install-on-request: 16,441 (30 days), 53,020 (90 days), 155,372 (365 days)
build-error: 0 (30 days)

This seems strange for a bug that was closed in 2018. I was able to use the workaround mentioned in this thread, but that help text doesn't look fixed to me.