I mean a command line executable, like cargo.

What is missing from the vcpkg command line executable?

I'm sorry that I didn't explain my question clearly.

Will vcpkg provide a installer in the future? instead of cloning a git repository? if not, what's the concern?

Which benefit do you expect from an installer? git is how versioning works in vcpkg (manifest mode). The executable is the only binary artifact.

And IIUC, Visual Studio comes with a manifest-mode-only bundled vcpkg.

My concerns are:

1. The speed of cloning the vcpkg repo from github is very slow in my area for some network reasons.
2. Cloning vcpkg repo and then do some bootstrap action is no easier than simply using a installer.

The speed of cloning the vcpkg repo from github is very slow in my area for some network reasons.

You don't have to clone the full history.
You can create more clones from a single local checkout.
If you don't use versioning, you could even download a tarball/ZIP archive.

And vcpkg is building packages from source. Downloads will happen all the time.

Cloning vcpkg repo and then do some bootstrap action is no easier than simply using a installer.

Hm, if typing two short commands isn't simple enough, then I wonder if using vcpkg will ever be simple enough.

Thanks god, I finaly found that scoop can help me do all the thing.
with a single command

scoop install vcpkg

scoop wiil dowload vcpkg.zip and run bootstrap.bat and run integrate install.
https://github.com/ScoopInstaller/Main/blob/master/bucket/vcpkg.json

There is a long record of issues hitting users of scoop...
https://github.com/microsoft/vcpkg/issues?q=is%3Aissue%20scoop