[BUG] Updating cargo-binstall through UniGetUI can never succeed on Windows (binary replaces itself)

[PowerUserZ]

Please confirm these before moving forward

• I have searched for my issue and have not found a work-in-progress/duplicate/resolved issue.
• I have tested that this issue has not been fixed in the latest (beta or stable) release.
• I have checked the FAQ section for solutions.
• This issue is about a bug.

UniGetUI Version

2026.2.7 (latest stable)

Windows version, edition, and architecture

Windows 11 Pro 10.0.26200 x64

Describe your issue

Updating the cargo-binstall package itself through UniGetUI (Cargo manager) can never succeed on Windows.

When cargo-binstall is present, UniGetUI runs every Cargo update as:

cargo.exe binstall <package> --no-confirm

(CargoPkgOperationHelper._getOperationParameters, OperationType.Update branch, UpdateVerb = "binstall" in Cargo.cs).

For the package cargo-binstall this means the running cargo-binstall.exe is asked to overwrite itself. cargo-binstall handles that case only when it downloads a prebuilt binary (upstream fix cargo-bins/cargo-binstall#712 for #702). When its fetchers time out and it falls back to cargo install cargo-binstall ("will be installed from source (with cargo)"), the fallback simply shells out to cargo install, which compiles for ~3 minutes and then fails to replace the locked executable:

   Replacing C:\Users\<user>\.cargo\bin\cargo-binstall.exe
error: failed to move `C:\Users\<user>\.cargo\bin\cargo-installAeQfV8\cargo-binstall.exe` to `C:\Users\<user>\.cargo\bin\cargo-binstall.exe`

Caused by:
  Access is denied. (os error 5)
ERROR Cargo errored! ExitStatus(ExitStatus(101))

Windows does not allow a running .exe to be replaced, so this path can never work. Every attempt leaves the old version installed, UniGetUI keeps listing cargo-binstall as updatable, and each retry costs a full source build. Stale cargo-binstall.exe~RF*.TMP files are also left behind in %USERPROFILE%\.cargo\bin.

Upstream tracks self-replace for the remaining cases in cargo-bins/cargo-binstall#1066 (open since 2023), so UniGetUI should not rely on cargo binstall cargo-binstall for this package.

Suggested fix

Special-case package.Id == "cargo-binstall" in CargoPkgOperationHelper and update it without going through the running binary, e.g.:

cargo.exe install cargo-binstall --locked --force

cargo.exe is a different file, so it can replace cargo-binstall.exe without a lock conflict. This is also the exact command Cargo.cs already uses as the binstall dependency installer ("cargo install cargo-binstall --locked"), so the code path exists.

Steps to reproduce the issue

1. Windows, cargo-binstall installed in %USERPROFILE%\.cargo\bin (as installed by UniGetUI's dependency prompt).
2. Wait until a newer cargo-binstall release exists (here: 1.19.0 -> 1.23.0).
3. In UniGetUI, Software Updates -> update "Cargo Binstall".
4. Update fails with exit code 70 after the source build; the installed version is unchanged.

Reproduced on 2026-08-16 (1.21.1) and 2026-09-11 (1.23.0). Manual workaround that works: cargo install cargo-binstall --locked --force from a terminal, or the official install-from-binstall-release.ps1 script.

UniGetUI Log

Package update operation for Package=cargo-binstall with Manager=Cargo
Update options: <InstallOptions instance (only non-default values are shown)
	RunAsAdministrator: True
	OverridesNextLevelOpts: False>
Version: 1.19.0 -> 1.23.0
Executing process with StartInfo:
 - FileName: "C:\Program Files\UniGetUI\Assets\Utilities\UniGetUI Elevator.exe"
 - Arguments: ""C:\Users\<user>\.cargo\bin\cargo.exe"  binstall cargo-binstall --no-confirm"
Start Time: "11.09.2026 17:35:20"
 INFO resolve: Resolving package: 'cargo-binstall'
 WARN resolve: Timeout reached while checking fetcher invalid url: deadline has elapsed
 (repeated x9)
 WARN resolve: Timeout reached while checking fetcher QuickInstall: deadline has elapsed
 (repeated x9)
 WARN The package cargo-binstall v1.23.0 will be installed from source (with cargo)
Updating crates.io index
Downloading crates ...
Downloaded cargo-binstall v1.23.0
Installing cargo-binstall v1.23.0
Locking 544 packages to latest compatible versions
...
error: failed to compile `cargo-binstall v1.23.0`, intermediate artifacts can be found at `C:\Users\<user>\AppData\Local\Temp\cargo-installiTKvt6`.
ERROR Cargo errored! ExitStatus(ExitStatus(101))
ERROR Fatal error:
  x For crate cargo-binstall: subprocess C:\Users\<user>\.rustup\toolchains\stable-x86_64-pc-windows-msvc\bin\cargo.exe install cargo-binstall --version 1.23.0 --root C:\Users\<user>\.cargo errored with exit code: 101

Operation history: Status=failed, ExitCode=70, "Cargo Binstall could not be updated".

Package Managers Logs

Same command run manually in a terminal (cargo binstall cargo-binstall) shows the underlying cause after the build finishes:

   Compiling binstalk-fetchers v0.10.48
   Compiling binstalk-registry v0.12.8
   Compiling binstalk v0.28.81
    Finished `release` profile [optimized] target(s) in 2m 53s
   Replacing C:\Users\<user>\.cargo\bin\cargo-binstall.exe
error: failed to move `C:\Users\<user>\.cargo\bin\cargo-installAeQfV8\cargo-binstall.exe` to `C:\Users\<user>\.cargo\bin\cargo-binstall.exe`

Caused by:
  Access is denied. (os error 5)
ERROR Cargo errored! ExitStatus(ExitStatus(101))
ERROR Fatal error:
  x For crate cargo-binstall: subprocess ...\cargo.exe install cargo-binstall --version 1.23.0 --root C:\Users\<user>\.cargo errored with exit code: 101

Relevant information

• rustc 1.98.1 / cargo 1.98.1, stable-x86_64-pc-windows-msvc
• cargo-binstall 1.19.0 installed (not a symlink; plain .exe in .cargo\bin)
• Update was run with "Run as administrator" enabled (UniGetUI Elevator).
• Related upstream: Self-update (bootstrap) via cargo binstall cargo-binstall fails on windows cargo-bins/cargo-binstall#702 (closed, prebuilt path only), WINGET: implement the COM API #712, [FEATURE REQUEST] Disable automatic updates for local apps and system components #1066 (open: use self-replace when self-updating).