注意:我在此处检查的时候安装的时候遇到了一个问题，内容如下
ERROR:While executing gem ... (Gem::RemoteFetcher::FetchError)
bad response Forbidden 403 (https://gems-ruby-china.b0.upaiyun.com/quick/Marshal.4.8/cocoapods-core-1.2.0.gemspec.rz)
无效的操作，推测应该gem版本有问题，可以用一下命令查一下ruby和gem的版本号：
$ gem -v
$ ruby - v
查看之后重新更新一下gem
$ sudo gem update --system
然后会显示Latest version currently installed. Aborting.这就是最新的gem已经更新了，你可以使用了。
三 安装成功
再重新安装CocoaPods
$ sudo gem install -n /usr/local/bin cocoapods
Last login: Sat Apr1 15:07:25 on ttys001
XLsn0wdeMac-mini:~ xlsn0w$ sudo gem update --system
Password:
Updating rubygems-update
Fetching: rubygems-update-2.6.7.gem (100%)
Successfully installed rubygems-update-2.6.7
Parsing documentation for rubygems-update-2.6.7
Installing ri documentation for rubygems-update-2.6.7
Installing darkfish documentation for rubygems-update-2.6.7
Done installing documentation for rubygems-update after 30 seconds
Parsing documentation for rubygems-update-2.6.7
Done installing documentation for rubygems-update after 0 seconds
Installing RubyGems 2.6.7
RubyGems 2.6.7 installed
Parsing documentation for rubygems-2.6.7
Installing ri documentation for rubygems-2.6.7
=== 2.6.7 / 2016-09-26
Bug fixes:
* Install native extensions in the correct location when using the
`--user-install` flag. Pull request #1683 by Noah Kantrowitz.
* When calling `Gem.sources`, load sources from `configuration`
if present, else use the default sources. Pull request #1699
by Luis Sagastume.
* Fail gracefully when attempting to redirect without a Location.
Pull request #1711 by Samuel Giddins.
* Update vendored Molinillo to 0.5.1. Pull request #1714 by
Samuel Giddins.
=== 2.6.6 / 2016-06-22
Bug fixes:
* Sort installed versions to make sure we install the latest version when
running `gem update --system`. As a one-time fix, run
`gem update --system=2.6.6`. Pull request #1601 by David Radcliffe.
=== 2.6.5 / 2016-06-21
Minor enhancements:
* Support for unified Integer in Ruby 2.4. Pull request #1618
by SHIBATA Hiroshi.
* Update vendored Molinillo to 0.5.0 for performance improvements.
Pull request #1638 by Samuel Giddins.
Bug fixes:
* Raise an explicit error if Signer#sign is called with no certs. Pull
request #1605 by Daniel Berger.
* Update `update_bundled_ca_certificates` utility script for directory
nesting. Pull request #1583 by James Wen.
* Fix broken symlink support in tar writer (+ fix broken test). Pull
request #1578 by Cezary Baginski.
* Remove extension directory before (re-)installing. Pull request #1576
by Jeremy Hinegardner.
* Regenerate test CA certificates with appropriate extensions. Pull
request #1611 by rhenium.
* Rubygems does not terminate on failed file lock when not superuser. Pull
request #1582 by Ellen Marie Dash.
* Fix tar headers with a 101 character name. Pull request #1612 by Paweł
Tomulik.
* Add Gem.platform_defaults to allow implementations to override defaults.
Pull request #1644 by Charles Oliver Nutter.
* Run Bundler tests on TravisCI. Pull request #1650 by Samuel Giddins.
=== 2.6.4 / 2016-04-26
Minor enhancements:
* Use Gem::Util::NULL_DEVICE instead of hard coded strings. Pull request #1588
by Chris Charabaruk.
* Use File.symlink on MS Windows if supported. Pull request #1418
by Nobuyoshi Nakada.
Bug fixes:
* Redact uri password from error output when gem fetch fails. Pull request
#1565 by Brian Fletcher.
* Suppress warnings. Pull request #1594 by Nobuyoshi Nakada.
* Escape user-supplied content served on web pages by `gem server` to avoid
potential XSS vulnerabilities. Samuel Giddins.
=== 2.6.3 / 2016-04-05
Minor enhancements:
* Lazily calculate Gem::LoadError exception messages. Pull request #1550
by Aaron Patterson.
* New fastly cert. Pull request #1548 by David Radcliffe.
* Organize and cleanup SSL certs. Pull request #1555 by James Wen.
* [RubyGems] Make deprecation message for paths= more helpful. Pull
request #1562 by Samuel Giddins.
* Show default gems when using "gem list". Pull request #1570 by Luis
Sagastume.
Bug fixes:
* Stub ordering should be consistent regardless of how cache is populated.
Pull request #1552 by Aaron Patterson.
* Handle cases when the @@stubs variable contains non-stubs. Pull request
#1558 by Per Lundberg.
* Fix test on Windows for inconsistent temp path. Pull request #1554 by
Hiroshi Shirosaki.
* Fix `Gem.find_spec_for_exe` picks oldest gem. Pull request #1566 by
Shinichi Maeshima.
* [Owner] Fallback to email and userid when owner email is missing. Pull
request #1569 by Samuel Giddins.
* [Installer] Handle nil existing executable. Pull request #1561 by Samuel
Giddins.
* Allow two digit version numbers in the tests. Pull request #1575 by unak.
=== 2.6.2 / 2016-03-12
Bug fixes:
* Fix wrong version of gem activation for bin stub. Pull request #1527 by
Aaron Patterson.
* Speed up gem activation failures. Pull request #1539 by Aaron Patterson.
* Fix platform sorting in the resolver. Pull request #1542 by Samuel E.
Giddins.
* Ensure we unlock the monitor even if try_activate throws. Pull request
#1538 by Charles Oliver Nutter.
=== 2.6.1 / 2016-02-28
Bug fixes:
* Ensure `default_path` and `home` are set for paths. Pull request #1513
by Aaron Patterson.
* Restore but deprecate support for Array values on `Gem.paths=`. Pull
request #1514 by Aaron Patterson.
* Fix invalid gem file preventing gem install from working. Pull request
#1499 by Luis Sagastume.
=== 2.6.0 / 2016-02-26
Minor enhancements:
* RubyGems now defaults the `gem push` to the gem's "allowed_push_host"
metadata setting.Pull request #1486 by Josh Lane.
* Update bundled Molinillo to 0.4.3. Pull request #1493 by Samuel E. Giddins.
* Add version option to gem open command. Pull request #1483 by Hrvoje
Šimić.
* Feature/add silent flag. Pull request #1455 by Luis Sagastume.
* Allow specifying gem requirements via env variables. Pull request #1472
by Samuel E. Giddins.
Bug fixes:
* RubyGems now stores `gem push` credentials under the host you signed-in for.
Pull request #1485 by Josh Lane.
* Move `coding` location to first line. Pull request #1471 by SHIBATA
Hiroshi.
* [PathSupport] Handle a regexp path separator. Pull request #1469 by
Samuel E. Giddins.
* Clean up the PathSupport object. Pull request #1094 by Aaron Patterson.
* Join with File::PATH_SEPARATOR in Gem.use_paths. Pull request #1476 by
Samuel E. Giddins.
* Handle when the gem home and gem path arent set in the config file. Pull
request #1478 by Samuel E. Giddins.
* Terminate TimeoutHandler. Pull request #1479 by Nobuyoshi Nakada.
* Remove redundant cache. Pull request #1482 by Eileen M. Uchitelle.
* Freeze `Gem::Version@segments` instance variable. Pull request #1487 by
Ben Dean.
* Gem cleanup is trying to uninstall gems outside GEM_HOME and reporting
an error after it tries. Pull request #1353 by Luis Sagastume.
* Avoid duplicated sources. Pull request #1489 by Luis Sagastume.
* Better description for quiet flag. Pull request #1491 by Luis Sagastume.
* Raise error if find_by_name returns with nil. Pull request #1494 by
Zoltán Hegedüs.
* Find_files only from loaded_gems when using gemdeps. Pull request #1277
by Michal Papis.
=== 2.5.2 / 2016-01-31
Bug fixes:
* Fix memoization of Gem::Version#prerelease? Pull request #1125 by Matijs van
Zuijlen.
* Handle trailing colons in GEM_PATH, by Damien Robert.
* Improve the Gemfile `gemspec` method, fixing #1204 and #1033. Pull request
#1276 by Michael Papis.
* Warn only once when a gemspec license is invalid. Pull request #1414 by Samuel
E. Giddins.
* Check for exact constants before using them, fixing Ruby bug #11940. Pull
request #1438 by Nobuyoshi Nakada.
* Fix building C extensions on Ruby 1.9.x on Windows. Pull request #1453 by Marie
Markwell.
* Handle symlinks containing ".." correctly. Pull request #1457 by Samuel E.
Giddins.
Minor enhancements:
* Add `--no-rc` flag, which skips loading `.gemrc`. Pull request #1329 by Luis
Sagastume.
* Allow basic auth to be excluded from `allowed_push_host`. By Josh Lane.
* Add `gem list --exact`, which finds gems by string match instead of regex. Pull
request #1344 by Luis Sagastume.
* Suggest alternatives when gem license is unknown. Pull request #1443 by Samuel
E. Giddins.
* Print a useful error if a binstub expects a newer version of a gem than is
installed. Pull request #1407 by Samuel E. Giddins.
* Allow the (supported) s3:// scheme to be used with `--source`. Pull request
#1416 by Dave Adams.
* Add `--[no-]post-install-message` to `install` and `update`. Pull request #1162
by Josef Šimánek.
* Add `--host` option to `yank`, providing symmetry with `pull`. Pull request
#1361 by Mike Virata-Stone.
* Update bundled Molinillo to 0.4.1. Pull request #1452 by Samuel E. Giddins.
* Allow calling `build` without '.gemspec'. Pull request #1454 by Stephen
Blackstone.
* Add support for `source` option on gems in Gemfile. Pull request #1355 by
Michael Papis.
* Function correctly when string literals are frozen on Ruby 2.3. Pull request
#1408 by Samuel E. Giddins.
=== 2.5.1 / 2015-12-10
Bug fixes:
* Ensure platform sorting only uses strings. Affected binary installs on Windows.
Issue #1369 reported by Ryan Atball (among others).
Pull request #1375 by Samuel E. Giddins.
* Revert PR #1332. Unable to reproduce, and nil should be impossible.
* Gem::Specification#to_fullpath now returns .rb extensions when such a file
exists.Pull request #1114 by y-yagi.
* RubyGems now handles Net::HTTPFatalError instead of crashing.Pull
request #1314 by Samuel E. Giddins.
* Updated bundled Molinillo to 0.4.0.Pull request #1322, #1396 by Samuel E.
Giddins.
* Improved performance of spec loading by reducing likelihood of loading the
complete specification.Pull request #1373 by Aaron Patterson.
* Improved caching of requirable filesPull request #1377 by Aaron Patterson.
* Fixed activation of gems with development dependencies.Pull request #1388
by Samuel E. Giddins.
* RubyGems now uses the same Molinillo vendoring strategy as Bundler.Pull
request #1397 by Samuel E. Giddins.
* Fixed documentation of Gem::Requirement.parse.Pull request #1398 by
Juanito Fatas.
* RubyGems no longer warns when a prerelease gem has prerelease dependencies.
Pull request #1399 by Samuel E. Giddins.
* Fixed Gem::Version documentation example.Pull request #1401 by Guilherme
Goettems Schneider.
* Updated documentation links to https://.Pull request #1404 by Suriyaa
Kudo.
* Fixed double word typo.Pull request #1411 by Jake Worth.
=== 2.5.0 / 2015-11-03
Major enhancements:
* Added the Gem::Licenses class which provides a set of standard license
identifiers as set by spdx.org. This is now used by the
Gem::Specification#license attribute to try to standardize (though not
enforce) licenses set by gem authors.
Pull request #1249 by Kyle Mitchell.
Minor enhancements:
* Use Molinillo as the resolver library.This is the same resolver as used by
Bundler.Pull request #1189 by Samuel E. Giddins.
* Add `--skip=gem_name` to Pristine command.Pull request #1018 by windwiny.
* The parsed gem dependencies file is now available via Gem.gemdeps following
Gem.use_gemdeps.Pull request #1224 by Hsing-Hui Hsu, issue #1213 by
Michal Papis.
* Moved description attribute to recommended for Gem::Specification.
Pull request #1046 by Michal Papis
* Moved `Gem::Indexer#abbreviate` and `#sanitize` to `Gem::Specification`.
Pull request #1145 by Arthur Nogueira Neves
* Cache Gem::Version segments for `#bump` and `#release`.
Pull request #1131 by Matijs van Zuijlen
* Fix edge case in `levenshtein_distance` for comparing longer strings.
Pull request #1173 by Richard Schneeman
* Remove duplication from List#to_a, improving from O(n^2) to O(n) time.
Pull request #1200 by Marc Siegel.
* Gem::Specification.add_specs is deprecated and will be removed from version
3.0 with no replacement.To add specs, install the gem, then reset the
cache.
* Gem::Specification.add_spec is deprecated and will be removed from version
3.0 with no replacement.To add specs, install the gem, then reset the
cache.
* Gem::Specification.remove_spec is deprecated and will be removed from version
3.0 with no replacement.To remove specs, uninstall the gem, then reset the
cache by calling Gem::Specification.reset.
* Call Array#compact before calling Array#uniq for minor speed improvement in
the Gem::Specification#files method.
Pull request #1253 by Marat Amerov.
* Use stringio instead of custom String classes.
Pull request #1250 by Petr Skocik.
* Use URI#host instead of URI#hostname to retain backwards compatibility with
Ruby 1.9.2 and earlier in util library.
Pull request #1288 by Joe Rafaniello.
* Documentation update for gem sources.
Pull request #1324 by Ilya Vassilevsky.
* Documentation update for required_ruby_version.
Pull request #1321 by Matt Patterson.
* Documentation update for gem update.
Pull request #1306 by Tim Blair.
* Emit a warning on SRV resolve failure.
Pull request #1023 by Ivan Kuchin.
* Allow duplicate dependencies between runtime and development.
Pull request #1032 by Murray Steele.
* The gem env command now shows the user installation directory.
Pull request #1343 by Luis Sagastume.
* The Gem::Platform#=== method now treats a nil cpu arch the same as 'universal'.
Pull request #1356 by Daniel Berger.
* Improved memory performance in Gem::Specification.traverse.Pull request
#1188 by Aaron Patterson.
* RubyGems packages now support symlinks.Pull request #1209 by Samuel E.
Giddins.
* RubyGems no longer outputs mkmf.log if it does not exist.Pull request
#1222 by Andrew Hooker.
* Added Bitrig platform.Pull request #1233 by John C. Vernaleo.
* Improved error message for first-time RubyGems developers.Pull request
#1241 by André Arko
* Improved performance of Gem::Specification#load with cached specs.Pull
request #1297 by Samuel E. Giddins.
* Gem::RemoteFetcher allows users to set HTTP headers.Pull request #1363 by
Agis Anastasopoulos.
Bug fixes:
* Fixed Rake homepage url in example for Gem::Specification#homepage.
Pull request #1171 by Arthur Nogueira Neves
* Don't crash if partially uninstalled gem can't be found.
Pull request #1283 by Cezary Baginski.
* Test warning cleanup.
Pull request #1298 by Samuel E. Giddins.
* Documentation fix for GemDependencyAPI.
Pull request #1308 by Michael Papis.
* Fetcher now ignores ENOLCK errors in single threaded environments. This
handles an issue with gem installation on NFS as best we can. Addresses
issue #1176 by Ryan Moore.
Pull request #1327 by Daniel Berger.
* Fix some path quoting issues in the test suite.
Pull request #1328 by Gavin Miller.
* Fix NoMethodError in running ruby processes when gems are uninstalled.
Pull request #1332 by Peter Drake.
* Fixed a potential NoMethodError for gem cleanup.
Pull request #1333 by Peter Drake.
* Fixed gem help bug.
Issue #1352 reported by bogem, pull request #1357 by Luis Sagastume.
* Remove temporary directories after tests finish.Pull request #1181 by
Nobuyoshi Nokada.
* Update links in RubyGems documentation.Pull request #1185 by Darío Hereñú.
* Prerelease gem executables can now be run.Pull request #1186 by Samuel E.
Giddins.
* Updated RubyGems travis-ci ruby versions.Pull request #1187 by Samuel E.
Giddins.
* Fixed release date of RubyGems 2.4.6.Pull request #1190 by Frieder
Bluemle.
* Fixed bugs in gem activation.Pull request #1202 by Miklós Fazekas.
* Fixed documentation for `gem list`.Pull request #1228 by Godfrey Chan.
* Fixed #1200 history entry.Pull request #1234 by Marc Siegel.
* Fixed synchronization issue when resetting the Gem::Specification gem list.
Pull request #1239 by Samuel E. Giddins.
* Fixed running tests in parallel.Pull request #1257 by SHIBATA Hiroshi.
* Fixed running tests with `--program-prefix` or `--program-suffix` for ruby.
Pull request #1258 by Shane Gibbs.
* Fixed Gem::Specification#to_yaml.Pull request #1262 by Hiroaki Izu.
* Fixed taintedness of Gem::Specification#raw_require_paths.Pull request
#1268 by Sam Ruby.
* Fixed sorting of platforms when installing gems.Pull request #1271 by
nonsequitur.
* Use `--no-document` over deprecated documentation options when installing
dependencies on travis.Pull request #1272 by takiy33.
* Improved support for IPv6 addresses in URIs.Pull request #1275 by Joe
Rafaniello.
* Spec validation no longer crashes if a file does not exist.Pull request
#1278 by Samuel E. Giddins.
* Gems can now be installed within `rescue`.Pull request #1282 by Samuel E.
Giddins.
* Increased Diffie-Hellman key size for tests for modern OpenSSL.Pull
request #1290 by Vít Ondruch.
* RubyGems handles invalid config files better.Pull request #1367 by Agis
Anastasopoulos.
=== 2.4.8 / 2015-06-08
Bug fixes:
* Tightened API endpoint checks for CVE-2015-3900
------------------------------------------------------------------------------
RubyGems installed the following executables:
/Users/xlsn0w/.rvm/rubies/ruby-2.2.2/bin/gem
Ruby Interactive (ri) documentation was installed. ri is kind of like man
pages for ruby libraries. You may access it like this:
ri Classname
ri Classname.class_method
ri Classname#instance_method
If you do not wish to install this documentation in the future, use the
--no-document flag, or set it as the default in your ~/.gemrc file. See
'gem help env' for details.
RubyGems system software updated
XLsn0wdeMac-mini:~ xlsn0w$ sudo gem install -n /usr/local/bin cocoapods
Fetching: nanaimo-0.2.3.gem (100%)
Successfully installed nanaimo-0.2.3
Fetching: xcodeproj-1.4.3.gem (100%)
Successfully installed xcodeproj-1.4.3
Fetching: cocoapods-1.2.0.gem (100%)
Successfully installed cocoapods-1.2.0
Parsing documentation for nanaimo-0.2.3
Installing ri documentation for nanaimo-0.2.3
Parsing documentation for xcodeproj-1.4.3
Installing ri documentation for xcodeproj-1.4.3
Parsing documentation for cocoapods-1.2.0
Installing ri documentation for cocoapods-1.2.0
Done installing documentation for nanaimo, xcodeproj, cocoapods after 6 seconds
3 gems installed
XLsn0wdeMac-mini:~ xlsn0w$ pod --version
1.2.0
XLsn0wdeMac-mini:~ xlsn0w$