Installing specific CocoaPod - 'no such file' while processing pre-install hook - cocoapods

Question

I installed MapBox on Mac OS X 10.9.1 with CocoaPods but I ran into a link problem and the MapBox people recommended that I download directly from a tag in their archive. Unfortunately, I cannot get that tag to load.
Here's my Podfile with their suggestion:
platform :ios, '7.0'
pod 'AFNetworking', '~> 2.0'
pod 'Mapbox', :git => 'https://github.com/mapbox/mapbox-ios-sdk', :tag => '1.1.0'
pod 'TWTSideMenuViewController', '~> 0.3'
CocoaPods gets an error on the pod 'Mapbox' line (see below). It does not seem to be able to find the directory. I tried:
fetching a particular :commit to see if it was that tag (no)
changing the directory names to have only alphabetic characters (did not help)
changing the Pod directory to allow writes by everyone (did not help)
re-installing CocoaPods with sudo gem uninstall cocoapods, sudo gem install cocoapods (I got 0.29.0 again, but did not help get the tag sources)
Why is the pre-install hook unable to find (or create?) that directory?
Here's the output from 'pod install':
[!] An error occurred while processing the pre-install hook of Mapbox (1.1.0).
No such file or directory - /Users/Bob/Documents/InfoBridge/projects/infobridge_aboutmywoods-ios/Pods/Mapbox
/Users/Bob/Documents/InfoBridge/projects/infobridge_aboutmywoods-ios/Pods/Local Podspecs/Mapbox.podspec:25:in `chdir'
/Users/Bob/Documents/InfoBridge/projects/infobridge_aboutmywoods-ios/Pods/Local Podspecs/Mapbox.podspec:25:in `block (2 levels) in _eval_podspec'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-core-0.29.0/lib/cocoapods-core/specification.rb:406:in `call'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-core-0.29.0/lib/cocoapods-core/specification.rb:406:in `pre_install!'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:489:in `run_spec_pre_install_hook'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:464:in `block (3 levels) in run_pre_install_hooks'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:462:in `each'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:462:in `block (2 levels) in run_pre_install_hooks'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:460:in `each'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:460:in `block in run_pre_install_hooks'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/user_interface.rb:113:in `message'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:459:in `run_pre_install_hooks'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:104:in `block in download_dependencies'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/user_interface.rb:52:in `section'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:101:in `download_dependencies'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/installer.rb:87:in `install!'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/command/project.rb:38:in `run_install_with_update'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/command/project.rb:68:in `run'
/Library/Ruby/Gems/2.0.0/gems/claide-0.4.0/lib/claide/command.rb:213:in `run'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/lib/cocoapods/command.rb:51:in `run'
/Library/Ruby/Gems/2.0.0/gems/cocoapods-0.29.0/bin/pod:24:in `<top (required)>'
/usr/bin/pod:23:in `load'
/usr/bin/pod:23:in `<main>'
Thanks, Bob

Answer 1

If you have previously installed Mapbox uninstall it first. Then install it again.
Remove or comment this line in Podfile
pod 'MapBox', '~> 1.1.0'
Run command
pod install
This will remove Mapbox and all it dependencies.
Put back Mapbox to Podfile
pod 'Mapbox', :git => 'https://github.com/mapbox/mapbox-ios-sdk.git', :branch => 'develop'
Run pod install again
It helped in my case

Answer 2

Remove podFile.lock and the problem is solved.