"Xcode quit unexpectedly while using the libswiftCore.dylib plug-in"

I've got similar issue fixed for my Xcode 7.2.1 by restarting my Mac.

One or more plugins need to be removed from this directory:

~/Library/Application Support/Developer/Shared/Xcode/Plug-ins/

To Fix:

Open the directory noted above and temporarily remove one or more of the plugins found.

Note:

Running the following command in Terminal as a non-sudo user will show the plugins impacting the startup:

open /Applications/Xcode.app/Contents/MacOS/Xcode

Sample errors produced after running the code in Terminal

2015-10-01 09:04:07.052 Xcode[860:42364] [MT] PluginLoading: Required plug-in compatibility UUID 0420B86A-AA43-4792-9ED0-6FE0F2B16A13 for plug-in at path '~/Library/Application Support/Developer/Shared/Xcode/Plug-ins/SwiftCodeSnippets.xcplugin' not present in DVTPlugInCompatibilityUUIDs
2015-10-01 09:04:07.054 Xcode[860:42364] [MT] PluginLoading: Required plug-in compatibility UUID 0420B86A-AA43-4792-9ED0-6FE0F2B16A13 for plug-in at path '~/Library/Application Support/Developer/Shared/Xcode/Plug-ins/CocoaControlsPlugin.xcplugin' not present in DVTPlugInCompatibilityUUIDs
2015-10-01 09:04:07.054 Xcode[860:42364] [MT] PluginLoading: Required plug-in compatibility UUID 0420B86A-AA43-4792-9ED0-6FE0F2B16A13 for plug-in at path '~/Library/Application Support/Developer/Shared/Xcode/Plug-ins/BBUUtilitiesTuckAway.xcplugin' not present in DVTPlugInCompatibilityUUIDs
Segmentation fault: 11