`-p` attempts to re-install the package

[natlibfi-arlehiko]

Problem

Running npx with the parameter -p executes npm even though the package is already installed. Adding --no-install doesn't help either. This makes using npx as opposed to node_modules/.bin/<some-command> much slower.

Reproduction

$ npm install istanbul babel-cli
npm WARN npm@1.0.0 No description
npm WARN npm@1.0.0 No repository field.
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.4 (node_modules/fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.4: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})

+ babel-cli@6.26.0
+ istanbul@0.4.5
added 4 packages from 33 contributors, removed 8 packages, updated 7 packages and audited 1589 packages in 2.892s
found 0 vulnerabilities

$ npx istanbul
Need a command to run
Try "istanbul help" for usage
$ npx --no-install -p babel-cli babel-node
npx: installed 237 in 3.512s
> 

[natlibfi-arlehiko]

Still occurs.

[silverwind]

Also seeing this with zopflipng-bin which installs the binary zopflipng. Because the package name differs from the binary name, I'm forced to use -p which seemingly makes npx ignore node_modules/.bin and in turn reinstalls the module on every execution. Example:

npx -p zopflipng-bin zopflipng

If node_modules/.bin/zopflipng exists, npx zopflipng works, but I can't use it because I specifically need thezopflipng-bin module.