.podspec error - source_files` pattern did not match any file

I had the same problem. I solved it by modifying that line to :

spec.source_files = "POD NAME/**/*"

The problem is that your podspec is referencing a commit that did not yet have the Classes folder,

i.e. this commit doesn't have a classes folder yet https://github.com/kevinrandrup/DropDownMenu/tree/09c9b3d515b78550557eabc0a8542f9f6f2623cf

You can fix this issue by referencing the latest commit, i.e. changing your podspec source to:

s.source       = { :git => "https://github.com/kevinrandrup/DropDownMenu.git", :commit => "0d6761feefccff1f7d8b7c7788ceb8e9cd1314ea" }
s.source_files  = 'Classes/*.{h,m}'

I used git tag. It worked well for me.

Step 1: Add tag

git tag 1.0.2 && git push origin --tags

Step 2: Set source with tag

s.source       = { :git => "https://github.com/kevinrandrup/DropDownMenu.git", :tag => s.version }
s.source_files  = 'Classes/*.{h,m,swift}'

Pay attention to that your tag must be equal to you pod spec version.

I got this problem after having CocoaPods generate the podspec file automatically for me with version 1.1.0 RC3.

The original line in the Podspec file was:

s.source_files = 'Pod/Classes/**/*'

I fixed it by changing it to:

s.source_files = 'NAME_OF_POD/Classes/**/*'