Ensure prefix subdirectories are created when installing

[charlespierce]

Closes #857

Info

• There is an upstream bug in npm@7 where global installs into a custom prefix will fail if the expected lib subdirectory doesn't already exist ([BUG] npm does not create --prefix dir npm/cli#2012)
• While this will likely get fixed, we can also work around it internally in Volta by ensuring the expected lib and bin directories are created before running an install.

Changes

• Updated the creation of the staging directory to ensure that the appropriate lib and bin directories are also created.

Tested

• Confirmed that installing packages under npm 7 works as expected.

[dherman]

LGTM!

[rwjblue]

Thanks for picking this up so quickly!

[DirtyF]

It still fails with some packages like gatbsy-cli:

➜ volta -v
0.9.1

➜ volta list --format=plain
package @11ty/eleventy@0.11.0 / eleventy / node@12.19.0 npm@built-in (default)
package gatsby-cli@2.12.111 / gatsby / node@12.19.0 npm@built-in (default)
package lerna@3.22.1 / lerna / node@12.19.0 npm@built-in (default)
package netlify-cli@2.65.7 / ntl, netlify / node@12.19.0 npm@built-in (default)
package tailwindcss@1.9.5 / tailwind, tailwindcss / node@12.19.0 npm@built-in (default)

➜ volta install lerna
success: installed lerna@3.22.1 with executables: lerna

➜ volta install vuepress
success: installed vuepress@1.7.1 with executables: vuepress

➜ volta install gatsby-cli
error: Could not install package 'gatsby-cli'

Please confirm the package is valid and run with `--verbose` for more diagnostics.

~ took 16s
➜ volta uninstall gatsby-cli
Removed executable 'gatsby' installed by 'gatsby-cli'
success: package 'gatsby-cli' uninstalled

~ took 6s
➜ volta install gatsby-cli
error: Could not install package 'gatsby-cli'

Please confirm the package is valid and run with `--verbose` for more diagnostics.

[charlespierce]

Hi @DirtyF, that looks like it may be a bug internally in npm@7 or in gatsby-cli: When I run npm i -g gatsby-cli I get:

$ npm i -g gatsby-cli
npm ERR! Cannot read property 'matches' of undefined

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/cpierce/.npm/_logs/2020-10-22T19_29_58_338Z-debug.log

Which is a JS type error, not something Volta can work around unfortunately. Confirmed that:

• Installing gatsby-cli with npm@6 works as expected
• Installing gatsby-cli with npm@7 while bypassing Volta's custom behavior also fails.

So my guess is it's a separate, unrelated bug within npm@7

[DirtyF]

Right, it's easy to switch from npm@7 to npm@6 with Volta ⚡

volta install npm@6
success: installed and set npm@6.14.8 as default

volta install gatsby-cli@2
success: installed gatsby-cli@2.12.111 with executables: gatsby