Making spec the argument of install

In https://github.com/pipxproject/pipx/issues/144, @raxod502 mentioned

I am quite confused why the package name I give pipx wouldn’t normally be passed to pip install. I don’t see any explanation of what the alternative is.

Why do we separately specify the package name and the requirement-specifier? For example, the API I wonder about is just copying pip’s interface:

$ pip install --help  

Usage:   
  pip install [options] <requirement specifier> [package-index-options] ...
  pip install [options] -r <requirements file> [package-index-options] ...
  pip install [options] [-e] <vcs project url> ...
  pip install [options] [-e] <local project path> ...
  pip install [options] <archive url/path> ...

The advantages are:

• A distribution name can be specified, or a url or a path.
• Any number of requirements can be specified.
• I don’t have to learn a new syntax, I can just use pip’s which I already know.

[itsayellow]

And this can be faster than a regular install of the package, because it works by installing using the --no-dependencies option to pip. So for package name determination you would only wait just for the main package to install and not for any of its dependencies to install.

[raxod502]

duplicating pip’s interface would mean pipx needs to create two venvs and throw one away just to discover the package name

Ok, but consider this: somebody is going to have to discover the package name. No reasonable user is going to realize to begin with that the package name is different from the Git repo name. So what’s going to happen is they will try to install it with pipx, hit this error, try using the Git repo as the package name after finding this issue, get another error when the package name doesn’t match, and then install a second time with the correct package name that they eventually figure out from looking on GitHub most likely. You still end up with two virtualenvs that were created, and it’s a heck of a lot slower because it’s the user doing the troubleshooting, instead of pipx. Why don’t we assume that the package name is the same as the Git repo, with a slower fallback, as part of the effort to discourage package authors from making poor packaging decisions?