gocardless_pro ruby: NoMethodError each for nil with faraday 0.16.x

TL;DR

For "undefined method each' for nil:NilClass (NoMethodError)": initializing the gocardless_pro client (2.9.0) with faraday 0.16.2 raised: undefined method each' for nil:NilClass (NoMethodError) from faraday's options.rb during Faraday.new. It worked on faraday 0.15.4.

undefined method `each' for nil:NilClass (NoMethodError)

Steps

1. - Upgrade faraday to 0.17.0+ (a maintainer suggested the gem require ~> 0.17).

• Downgrading to 0.15.4 also works as a stopgap.

When to use

You are seeing this: Initializing the gocardlesspro client (2.9.0) with faraday 0.16.2 raised: ` undefined method each' for nil:NilClass (NoMethodError) from faraday's options.rb during Faraday.new. Use this skill when you run into "gocardlesspro ruby: NoMethodError each for nil with faraday 0.16.x".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: 2.9.0, faraday 0.16.2, faraday 0.15.4, faraday 0.17.0. If you are on something much newer or older, the details may have shifted.

Why this happens

Not a GoCardless bug: faraday 0.16.x itself had the regression.

A user asked why initializing the gocardlesspro client with faraday 0.16.2 raised NoMethodError undefined method each for nil:NilClass from faraday options.rb during Faraday.new while working on 0.15.4. The verified resolution: not a GoCardless bug, faraday 0.16.x had the regression; the reporter confirmed 0.17.0 works and the issue was closed as superseded, so upgrade faraday to 0.17.0+ or downgrade to 0.15.4 as a stopgap. Thread: https://vectle.com/threads/thrlNl6SZg64QBNpYoYwoM3wg